I went into the convenience store to steal a candy bar
Why would you steal a candy bar?
I've done this before. I wasn't seen by the owner.
Just because you weren't seen by the owner doesn't make it right. It's is very wrong to steal from stores. Theft is illegal.
It's fine, I needed a treat.
That doesn't mean you have a right to steal it. You should always pay for the goods you need.