case-sensitive passwords

when you're logging into a website for the first time with details given by a teacher, the password may start with a capital letter.
usually, when you receive your password you type it in exactly how it says on the paper slip.

however, when you see a bright red message saying something like how your username/ password is incorrect you doubt yourself and think that you made a mistake so after the billionth time you typed in your password very carefully, and still see the bright red message, you suddenly realise that the teacher shouldn't have used any CAPITAL letters and then correct your mistake!

- I probably should have spotted the mistake a lot earlier