You can be a master in many things, but only the zen master has mastered the journey of life. We are created as souls in the physical realm in suffering to find our bliss. Because of our suffering, we're attached to desires. Because of our attachment to desires, we put a lot of time into creating our ego. Then we become attached to our ego and we have to live in fear of losing it. But bliss can only shine through, when our soul is free of our ego. Only when we know that we are not our ego, we can become aware of our divine nature, our soul. Our soul's journey also is absolutely irrational, whereas our ego tends to insist on making existence rational. To find bliss, we have to become aware of our suffering, this is why zen is not an easy path to travel on. Souls are travelling it on different stages, birth and death do not separate our soul's journey, they're just gateways into other dimensions. We can follow our desires in the physical realm, but this will only ease our suffering because it tightens our ego in the physical realm and hides our bliss in the enlightened/psychedelic/universal spirit realm. The more our souls becomes sensitive to its enlightenment, the more it becomes aware that what the soul is doing in the physical realm has an effect in the transcendental realm. In the journey of life, our spiritual enlightenment and bliss is the ultimate end of our soul's suffering, and those who have seen their suffering and found their bliss within themselves, have mastered the journey of life and the path of zen.