Upekkha,
With me what you call ‘aha’ moments come in both situations you mention. In my case they are modified somewhat:
1) when I am thinking about a totally different thing, even a very mundane one, and up pops something about Dhamma I had been contemplating well before. Usually it turns out to be a significant point I had missed before
2) The other case is when I am writing a post on here. I do not talk out loud at all. I do no formal meditations – I am by nature averse to anything requiring laid- out methods and structures; in short, anything ‘formal’. I see it as forcing it on oneself and feel it to be quite out of time and out of place.
As to your question: to me any situation that takes you deeper into Dhamma IS meditation.