Best to live lightly, unthinkingly.
Your mistake was not in imagining things you could not know—that is, after all, what imagination is for. Rather, your mistake was in unthinkingly treating what you imagined as though it were an accurate representation of the facts.
Words really flattering are not those which we prepare but those which escape us unthinkingly.
It's not just about a coach telling you what to do and just following it unthinkingly.
As adults, we do know more, but we don't know enough. People can be very unthinkingly callous.