We Need to Remember Problems We Solved

I need your help. I’m trying to find a phrase to describe an important phenomenon and maybe help people recognize it more easily. The phenomenon is this: When we fix a problem, we forget it. I don’t mean you and me in “we” — we, of course, remember. But pop culture forgets, and the mass media forgets, and young people never learn about the problem or how it was solved. 

Maybe this will make more sense with examples. Have you ever seen a bald eagle? They almost went extinct! And now they’re everywhere...