One of the worst "hints" I ever encountered was: To get an idea of what's going on in a paragraph, read the first sentence and the last sentence. This gave me

One of the worst "hints" I ever encountered was: To get an idea of what's going on in a paragraph, read the first sentence and the last sentence. This gave me the illusion that I could understand what was going on in a text by skimming. And you can't do this reliably. [It doesn't work /at all/ with mathematics or serious CS]. A very hard habit to break. I wish I'd never learned it.