Many times, when you fill out a registration form and miss a required field, the form reloads with all the fields filled out except for the password which you have to retype.
I'm wondering if I should do the same. I really prefer not to, because as a user I'm very annoyed by the need to retype the password.
Is it a security measure? What does it protect from?
EDIT: Helping the user remember the password is important, but does not answer the question. Most forms have two password fields anyway, and I see no reason to make the user type the password 4 or 6 times instead of 2.