Is Zen explosive?

When I first read Zen stories, I was confused by the way monks became enlightened as though struck by lightning just because the master made some apparently trivial remark. "Have a cup of tea!" the master would say, the monk instantly became enlightened. Why?

Actually, it doesn't happen like that. You spend many years practicing zazen and your understanding gradually deepens. Then something may happen that causes the dam to break and lets the light flood in.

~ Zen Questions ~

~ Robert Allen ~