It’s not so much that men have “forgotten” God, it’s that they have actively sought to obliterate Him in government, commerce, education, the arts, our daily lives, and even to some extent, in our churches.
Agreed; an outright rejection and rebellion against God, and so young ones grow up in ignorance and confusion.
Remember when the Democratic party meeting, I think to discuss their platform, was asked about leaving (or adding?) “God” in the platform - there were three voice votes, all shouting “NO!”
They doomed themselves.