That's funny, because I grew up canoeing and have never on my own flipped one - other people in the boat doing dumb stuff, of course, or trying something silly in white water (maybe that counts as "on my own"?), sure - but I feel totally stable and comfortable in a canoe. Kayaks, though? Man, they're trying bite me! I've never felt like even the most stable beginner-friendly of kayaks wasn't trying to throw me off it.

I think the difference is stroke technique? I'm sure I'm instinctively trying to paddle a kayak like I would a canoe, and they don't like that. If I had more opportunity I'd get someone to teach me proper kayak stroke shapes, and then they'd probably feel more friendly.