sure.
Examples:
You have plans to meet your friends after work on Tuesday. Your girlfriend says "I don't want you to go, come over and see me Tuesday night instead."
A confident guy says "Sorry, but I already have plans ... I can see you Wednesday if you'd like"
A doormat cancels his plans with his friends and goes to see his girlfriend instead.
Your girlfriend sees an expensive ring that she really likes in a store. She knows you can't afford it, but tries to get you to buy it anyway.
A confident guy says "I can't get that for you now" and probably remembers it for her birthday.
A doormat buys her the ring and eats cheese sandwiches for a month because he has no money left.
Your girlfriend starts a fight over a small disagreement.
A confident guy says "Stop your bullsh*t and stop being a brat."
A doormat says "You're right, I'm sorry!"
Carl.