Aha! Watching people as they are struck by sudden insight
Everybody loves those rare "Aha moments" where you suddenly and unexpectedly solve a difficult problem or understand something that had previously perplexed you. But until now, researchers had not had a good way to study how people actually experienced what is called "Epiphany learning." Ref. Source 9j.
I have too many of these "Epiphany" moments to count. There is no better feeling than staring at a problem for hours, then finally having a single second where everything makes since. I mostly experienced this when I was going through organic chemistry in college.