Earlier quoted context omitted.
> I never remember if f-h will move me to |hello or to h|ello. …Isn't the answer "neither"? If the cursor is somewhere before that `h`, then doing `fh` will put the cursor on that `h`. If you want to enter insert mode before that `h`, you would press `i`, or `a` to enter insert mode after the `h`.
That's half-right, I think. The question is, when using a command like "change until" or "change forward", i.e. 'ct' or 'cf', what will the effect be? In the case of 'ct', you're going to delete up until the letter, whereas in 'cf', it will include the letter you're targetting.
> The question is, when using a command like "change until" or "change forward", i.e. 'ct' or 'cf', what will the effect be?
Is this a question? You answered it accurately. The behaviour is consistent here too, though the mnemonics people often use don't always make total sense.