Hah that's funny... I'm literally sitting here waiting for a call to go meet a guy and return his wallet that I found in the middle of the street. Hope it goes well, not looking for a reward or anything.
I've had a variety of lost and found experiences over the years though. Returned a wallet with over $700 to a guy at my gym; he barely even took a second to thank me and just went on with his conversation with someone else. Returned a smartphone to a lady who was mostly shocked (and maybe a little embarrassed about some of the pictures she had on her unlocked phone...). Only regretful experience I've had so far is another time where I turned in a new (at the time) iPhone to a store's customer service counter instead of tracking down the owner myself; I left with a bad feeling that the person behind the counter wasn't going to put as much effort into finding the owner as I would.
Your feeling is one I would share. They probably won't.
My experiences are similar. People really vary in their response to a good deed directly favoring them, and I suspect the nature and quantity of deeds they do can be correlated to those responses.
