It's actually interesting to wonder about that. Whether candy and snacks you enjoyed as a kid don't have the intense taste you remember because you don't have a child's sensitive palate anymore or the overall decrease of refined sugar content due to new regulations. It could well be a combination of both, depending on the case.
(Incidentally, the above is why children dislike bitter/pungent food like green bell peppers and coffee. Also the origin of the "kids hate greens" stereotype is that cheap flash-frozen, oxidized vegetables taste like copper to them. Unlike most adults, they can tell something is off.)