Define Epiphany.

How do I define 'epiphany?'
In this context, my epiphanies are random ideas that come to me during lectures. Specifically, these epiphanies are the ones that I thought were important enough to write down in the margin of my notebook. 
Exactly why do I have so many epiphanies?
One of my favorite pastimes is daydreaming. It’s what I do best. Nothing feels better than a lightbulb going off inside your head. 
Honestly, I think I just don’t write down the other epiphanies I have, if one is completely convinced that the atmosphere of the Linguistics lecture has nothing to do with it. Every time I’m not having an epiphany in that class, I’m either 1) thinking about love, 2) paying attention, or 3) sleeping.