Lindsay Lohan -- Rehab All-Star

Lindsay Lohan was expected to screw up again in rehab -- at least that's what we here at TMZ thought -- but to our amazement, she's actually become a model patient this time around.

Sources close to Lindsay tell us, the actress has been attending ALL of her group and one-on-one counseling sessions at Betty Ford -- and she's not only taking them seriously, she's talking to friends about what she's learned ... especially issues involving self-control and reckless impulses.

Lindsay is saying the program is getting more complicated and emotional, but she's not shying away.

We're told Lindsay is sleeping in a room with two roommates because she doesn't want to be alone. Get this -- there's no drama -- she's getting along with both.

Several people who have visited her at Betty Ford tell us Lindsay looks better than she's looked in a long time.