A cheatsheet is like a reference page, with the difference that it provides a quick lookup of the most common features. I really like this pandas cheatsheet for that reason. When I haven't done data-wrangling or cleaning in a while, it helps me to get a quick answer.

One other benefit I've discovered is that it helps with memory retention. I don't have to spend a lot of time searching for something and can quickly get back to the task at hand. That helps me retain what I found on the cheatsheet instead of feeling somewhat exhausted by the search.