Yes, you make your own sheets of the things you can never quite remember.

Often going through that process leaves you remembering them.

These cheetsheets aren't meant to be printed off and carried into your open book tests. They are meant to be greppable formula lookups. They're useful if you can define the problem but don't know the equation off your head to solve it. Think something like differentiating a trig function after you haven't used it in a while or looking up some statistical approximation.

I do. Mainly for things I don't really intend to memorize. It's just an easier reference than, say, a man page.

Pretty much anything is easier to reference than a man page :) I wish the standard for man, would be to include examples. But maybe I'm in the minority of people who learn by example.

> would be to include examples

strongly agree. Some do but not all, so you can't rely on it. Those tldr sites are reasonable alternatives for most commands.

They tend to be a great resource for rarely used knowledge.

The key is remembering you have a cheatsheet for that rarely used knowledge.

Math cheatsheet made by others are not very useful. When it's not about a large public API it doesn't really make sense. People also forget that most theorems/formulas have slight modifications that are very useful but make these kind of enterprise very difficult.

Same for me. I need to start with the bulk of the info and start to compress it to be helpful to me.