The highs are few and far between, and generally involve people being unexpectedly introspective and intelligent in their assertions (even if I disagree with them). The worst interactions are most of the interactions. That is, engaging someone of a differing opinion is unlikely to lead to any kind of shared consensus, and very likely to lead to irrevocable loss of respect, even to loathing. The worst is probably seeing that friends have completely reversed their personalities and been sucked into the hole of conspiracy fantasies and bigoted hate. Makes me wonder if they really did change, or if I just didn't know them very well to begin with.

Sometimes it seem like the Internet is like the Babelfish: “Meanwhile, the poor Babel fish, by effectively removing all barriers to communication between different races and cultures, has caused more and bloodier wars than anything else in the history of creation.” (Douglas Adams)

Can you think of one particular instance for each?

One recent one was a discussion regarding the Mueller investigation, where the other person stated that the investigation proved it had no evidence to support indictments because it had tried to block a motion for discovery. When I pointed out that prosecutors often try to block discovery, and that a reluctance to divulge (and assist the defense) is not the same as having no evidence, and that it would require a judge to make a determination as to the validity of the delay in discovery requested, the other person actually conceded the points and said that I was probably right about Mueller's motivations. That's such an incredible, unexpected rarity in this age of strident troll screaming, I was quite taken aback.

An example on the bad side was a friend who has started idolizing a far-right provocateur in England named Tommy Robinson, founder of the EDL, which inspired Anders Breivik to murder seventy-seven people, including a large number of children. This has become a pattern of some fairly rabid anti-Muslim hatred on this friend's part, and this was a person that I had never considered bigoted before. I'm sure he doesn't consider himself that way even now, but the news sources he's quoting and the theories he's espousing emphatically say otherwise. I no longer really see much hope that he will take a step back from the conspiracy theories, cast a wider net in his chosen sources of news and try for some more balanced, compassionate reactions.

How dumb was I ten years ago? I've been on the Internet for more than 30 years, so I'd have to go back a bit to be particularly dumb. Even then, though, alt.fan.furry struck me as INSANELY dumb. Every time I get sucked into an argument with an anonymous troll, I do feel pretty dumb. Fortunately that happens less often than it did decades ago. But I was dumb enough to allow arguments to go on for days, weeks or even months, not being aware that there would never be any chance of convincing the other person of anything (or slim chance, as the first example above demonstrates)

highs-discovering jonathan
lows-the time before that
xP

okay, in seriousness:
my interactions online are surprisingly similar to my interactions offline,
i'm more of an observer, but will happily talk if talked to
not much to add to the conversation here. however i do feel like i experience interactions in a similar manner to more.. interactive people, even if my actual interaction is not as conversational as most.
it is still a matter of being inspired by others. only instead of the conversation being directly personal, i make an impersonal statement, or creation, somebody has put out there, into a personal one, through my own analysis of it. i can learn from it.
the first paragraph is only half a joke- even though we have not interacted on a deeply personal level, i feel i've learned much and am grateful for what you publicly share.

there isn't much to say about bad things. given that i'm a generally detached observer, as well as an actual soul-less machine, i hardly get personally affected by dumb shit online. even the worst interactions i can think of, which were indeed interpersonal interactions between me and another party, have not affected me much.
just your run of the mill disrespect or overly sensitive people beind unable to deal with the non-existent rivers of compassion they'd expected from me.
sorry, dead dragons don't have feelings! they can get inspired, though.

I've had many unpleasant experiences on the Internet, but I think the worst one was from when I was a wee young child with few, if any, real life friends. Most of my friends were on the Pokemon Paradise message board and on AIM, and one of them that I had a love-hate relationship with was like a prototype of an emo kid from California, I think his name was Greg. Greg got prudishly angry at me once and threatened to print out chat logs of my 11 or 12 year old promiscuity (through roleplay) and send it to my mother. I got so upset that I actually ran to the bathroom and vomited because I was crying so hard. It's hard to think of any other instance where something that happened online upset me that much.

I've done my fair share of stupid shit on the Internet too. Circa 2008 (can't believe that was 10 years ago), I was spending more time talking with "Send bobs" type of people on the Internet than paying attention to my college work and trying to get help with passing my Accounting class (the bane of my existence back then). To be fair, college was my first taste of freedom from overbearing parents, like my stepdad who would threaten any guy I brought home with, "If you break her heart, I'll bury you down so deep that the crows won't even be able to find you", so it's understandable that got a little carried away.

One of the highlights of my time on the Internet was being able to find like-minded people, whether it was the people who shared my bizarre fetishes when I was 15 or being able to connect with furries around the world once I accepted my furryness around 2012. Before both things happened, I felt really isolated and alone in the world. As much as it's going to sound like sucking up and I don't mean it to, finding the Drink'n'Think through your FA posts helped me cope a lot with the current world and rediscover that there are still open-minded, non-hostile people on the Internet with whom I can discuss matters without it turning ugly, even if I don't necessarily agree with them. I've been able to get into a better mental headspace and don't take things to heart nearly as much as I used to, and it's easier to see the good in humanity again when one isn't constantly terrified of people having ulterior motives.

What's one of the worst interactions you ever had online?
- It'd be hard to pick one. Probably when, years ago, I reached out to my irl social network through myspace seeking financial assistance only to be completely ignored.

How dumb were you ten years ago on the internet?
- I don't know about dumb. Maybe less cynical. I've had a rule for a long time, which is that I don't relate anything online that I wouldn't be willing to say face to face with someone who I've interacted with a similar number of times or to a similar level of depth.

Was there ever a moment online that gave you a sense of hope in humanity?
- Conjuring up enough money to stop my house being foreclosed on a few years ago.

Other high points in my online interactions have been the times I've talked someone through a difficult time, including a few times I've talked someone down off a ledge.