Why am I or am I Not or Am I Registered? Or What? (Edie Brickell)

I don't know whether i am a registered user or not - I type my info in every time (like above - user name and email address), but when my posts are greeted with the "Success! Care to save time and have info appear automatically?", well, when I try it says my name is already registered. Which means, I guess, that I am registered but still typing name/email address in every post. Which MIGHT be directly responsible for the rambling, incoherent nature of some of my posts.
How can I post w/out reentering the same info? I'm kind of a luddite, so...any help will be appreciated. Thanks. Alison