I'm going shopping at the lost and found table
Why would you take someone else's things from the lost and found?
Someone's loss is surely to be my gain
Please think how you would feel if you lost something of yours. It's wrong to take things that do not belong to you, even if they are lost. It's basically stealing.
What about the people who don't know about the lost and found?
Try to not get into the habit of taking things that are not yours. While it is a lost and found, you are still stealing since the item was not yours to begin with.