I fail all the time. Oops, forgot to change my keyboard layout back or 'is it flamingmonkey1, 2, or 3 this time?' (because I have to rotate it every N months and clearly I'm not going to keep generating new passwords that I have to remember, unless the security people really explain why, which they never do), or 'oops, capslock was on', or 'does this password prompt require special characters (is it flamingmonkey1!?) or does it ban them? (or worst of all 'is whatever validates passwords just broken mysteriously and I have to reset my password to fix it?')

There's so many reasons I get passwords wrong. (it doesn't help that work has 4 systems that all use different passwords, all with different requirements).

If you locked me out (without me being able to easily unlock myself), I would immediately consider this an even-more-hostile relationship than normal and would immediately respond in kind.