What do you think of me stealing and chewing a stranger's last piece of gum then putting it back in the package because I felt bad.
If you feel bad, do you think putting the gum back is a good idea?
Yes, I apologized and always feel bad when I'm taking the last gum.
You are remorseful about stealing and that means you will have tried to stop it from happening again. This is a good idea to stop it because if you get caught by the wrong person they will see you in court. However, it is unhygienic to put used gum back.
I'm sorry if it gross but it's the truth
Apologizing and feeling sorry is appropriate for what you did. You've hopefully learned a lesson here and I hope you are more conscientious about your pranks in the future.