Comment by theshrike79

I "purge" - or better yet choose not to retain - the data.

BUT, BUT! I keep the index.

My favourite quote from Donald Rumsfeld (a very bad human being, but this is still good)

> Reports that say that something hasn't happened are always interesting to me, because as we know, there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns—the ones we don't know we don't know. And if one looks throughout the history of our country and other free countries, it is the latter category that tends to be the difficult ones.

What I optimise for is to have as many "known unknowns" as possible. I know a concept, process or a tool exists, but don't understand it or know how to do it. But because I know it exists, I won't start inventing it again from scratch when I need it.

Like if one needs to do some esoteric task, they might start figuring it out from scratch. But because the index in my brain contains a link ("known unknown") to a tool/process that makes that specific thing a LOT easier, I can start looking into it more.

Or I might need to do something common like plumbing or some electrical work at home. Do I know how to do that? No. But I Know A Guy I can call, again externalising the knowledge. Either they come over and help me do it or talk me through the process of adjusting the thermostat in my shower faucet (you need to use WAY more force than I was comfortable with without an expert on the phone btw... there are no hidden screws, you just rip the bits off :D)