They say that smell is the most evocative of the senses, the one that's most likely to make you remember something. I think there's something to that; it's been years since I used one of those little color pellets you get from PAAS, but the smell of vinegar still makes me think of hard-boiled eggs and the little bent-wire dipper that comes in the kits.
The funny thing is, I don't even like hard-boiled eggs all that much. The fun's all in the dyeing. Which is probably why I'm into pysanky these days, as it means I can use the egg contents for something else.