Re: …Honesty…
Haraam income is what we should always avoid. Imagine if you had taken that money, what if you lost a larger amount in the shape of robbery, physical loss, health loss etc. and you end up paying twice or 3 times of that amount in medical bills etc.? Was it really worth it?
You are still young and when I was your age, I also used to get happy saying hey look I found money! But now I also look at it differently. Sometimes it’s a test and we must try to pass it.
The other day 2 guys were using the self checkout machine at wal mart and they took the change but left 2 dollar bills in the machine (they are dispensed in a different place than coins). They walked off and I said “Sir” but they didn’t hear/understand. They were hispanics. I used my hispanic skills that I had learned in school and they were able to hear me and understand 
They were very glad.