Our sense of smell contributes so much more to our life experiences than we know, and even though we're more likely to remember a foul stench than a good smell during our days we often remember key points by smell.
And that's why we have so many smell memories associated with childhood- those are our formulative years, when everything is new and smells good and bad are a memorable sensory discovery.
Who could forget how that box of crayons smelled when you opened it, or the oddly calming smell of a jar of paste? That one's a much more vivid smell memory for those who ate the paste than it is for those who didn't, memorable like the smell of a freshly opened can of cheese puffs.
Yeah, that's a doozy of a smell, ain't it? But to me the best smells of childhood were contained in those rad scratch n sniff stickers, which came in a seemingly never ending range of flavors from pickle to cowboy boot.