Yeah Brian, I'd say it exists, but to differ with Hush, I'd say that it's not just the parents or adults that change, but teens and younger as well...it's just harder to spot while you are going through it.
Now, if you originally meant Generation Gap, I can see several, and I do think they exist. There's one between my parents and I, based on life experiences and how they were raised...whole different era (pre-1950). And, I can see one between people my age and those younger (post-1980). FYI, I was born in 1970, and believe me, I see the difference in culture, society, values, ethics, and tastes. But I digress.
On the topic at hand, I think it's more of the teens detaching from parents than vice-versa, as they seek their identities, personalities, and freedoms, trying out wings and having experiences they somehow feel no parent or adult has gone through. It's not that the older people have forgotten what it's like to be a kid or teen, but rather the teens thinking the parents don't understand. The lady I live with has a teen daughter, and although Jen feels she can't talk with her mom about anything since her mom obviously doesn't understand her, Pat was very much like Jen when she was a teen, and had similar, if not identical, problems, thoughts and issues during her own teen years. But Pat trying to talk to Jen about life is pretty pointless. It's human nature not to believe the stove is hot until you touch it, and life experiences can only come that way...through living them. And, with the above life example, it's not so much a Generation Gap, but a Communication Breakdown, though that is an over-simplification of the familial variables in every single child-parent relationship, which can be highly complex, not to mention convoluted.
“It is not the strongest of the species that survive, nor the most
intelligent, but the one most responsive to change.” Charles Darwin