Only by mistake
When I've forgotten my password
If I'm afraid my post might cost me precious XP
If I'm being obnoxious, obstreperous, and rude
Several of the above
All the time, as I'm too lazy to login
All the time, as I've never registered
All the time (for some other reason than above)
Results (388 votes), past polls
By rote learning.
Via Genetic memory.
It's provided by my firmware.
I just remember them.
Thirty days hath September
My computer gets it right, usually.
I just ask someone else.
Someone punches me on the first of the month.
Results (371 votes),