Is it wrong that I wish I didn't give my extra pair of earbuds to someone who lost his?
Why did you give them to him then?
Because he is a moochie and he usually makes problems on the bus with noise
It is okay to feel bad to have given something to somebody who is normally a mooch. But it seems you did it for a good cause.
Well probably not
It's normal to feel regret for giving something away that you may have needed. All you can do is use this as a learning experience and try not to feel too bad.