[kragen]

> 5 years go by and you've not touched the subject in any meaningful way so of-course if someone asks you to write a Red-Black Tree or implement Quick Select you probably will not be able to do it from the top of your head.

Well, don't let five years go by without touching the subject. Occasionally practice the things you once learned, integrate them into your larger body of knowledge, and you'll never forget how red-black trees and quickselect work --- even if you never implemented them from scratch.