Oh, all right. I'll bite.
Since I was sixteen I've had an intellectual appreciation of notself, and accepted it as my position. Over the years I seldom meditated, and poorly when I did. However, I would habitually reflect on feelings, emotions, thoughts, experiences to see if they were something I could call self. During that time I think I got a pretty good feel for what wasn't really part of my identity, and didn't see anything that was solid or permanent, lasting, etc. Figured I had this down pat.
Well, after I started to meditate properly and get some skill at it, I took up the cemetery contemplations. The second one, I think it is, is where the corpse is being consumed by wildlife... so I had a pretty good mental image going on, and then I wondered, out of the blue: "why would they eat that" It wasn't that I doubted a dog or bird would eat decaying flesh. Rather, I wondered why they need to eat at all. Then I contemplated what they were ingesting and what happened to it once it was consumed. Then I had a rather complete insight: they accumulate to their forms, all the while shedding from their forms... food goes in, bodies grow, heat is produced, waste is expelled, they go on, eventually dieing and also being consumed. The implication was clearly that all that I had, bodily, was accumulated in the same way, and when life left it, it would be very quick for all that I was calling 'my body' to be stripped and redistributed. If I died in the jungle, all that was 'mine' would be scattered across a hundred square miles by day break. So much for all my tender care of the body. Almost immediately I had another image arise in my mind, and it was that of an embryo, and I realized I had accumulated and shed since my conception ... at no point was I not accumulating or shedding, and was doing both all the time... my body was in flux at every moment, as are all bodies. At death the accumulation stops, but the shedding continues until there is nothing left to call 'me' or 'mine', although other beings would certainly call it 'theirs' and 'themselves'.
While all this is intellectually unsurprising, there was a shock when I realized it. That was the day I really appreciated how ignorant I was: totally overlooking the obvious.