One - perhaps the only? - benefit of getting old is realizing we don't know beans. It's understanding that learning more about stuff we think we already know enough about usually is worth the effort.
For instance, take phrenology - the study of bumps on a person's head. We're all learned to smile at such a dumb idea. The shape of your skull is supposed to reveal your intellectual or even your moral capabilities? What a laugh!
Well, pervasive as phrenology was during much of the 1800's and even beyond, it was a laugh. But the basic idea - that certain bodily functions are regulated by certain parts of the brain - remains important to this day.
Phrenology was the brain-child (heh) of one Franz Joseph Gall (1758-1828), one of the leading neuroanatomists of his time. The dude did his homework. He dissected the brains of naturally aborted fetuses, heinous criminals, celebrated persons, and other types of animals, and grew a theory. Part of it involved realizing that fetal and newborn skulls are soft - and so could be pushed outward by growth of brain tissue beneath. Gall knew enough to understand that, in adults, the size of brain parts didn't exactly match cranium shape, but he thought that shape came close enough to matter.
He was, very basically, wrong. And some later scientists testing his theories in the 1800's conducted horrific experiments on unanestheticised animals. You don't want to think about it. Yet Gall was not a bad guy. His basic idea - that the parts of a brain are localized in function - not only remains accepted today, but also served 200 years ago to yank thinking about mentality out of metaphysics and into science.
Of course, it also reminds us that modern science also is likely to need, as time goes by, a whole new bunch of yanks.