It happens to me from time to time, but I learned a big lesson a few years ago at one particular site.
A lesson I already knew but this experience really brought it home.
This was what I call a linear park, houses lined up along the opposite side of the street but on this side there was the remains of a part of an overgrown driveway of at least one house and there could have been a couple more around there in the past.
Not very wide, just enough area from the street to a creek that ran behind in the back for a small backyard and a normal but not huge front yard and this strip ran about 3/4's of a block long.
The city knocked down any houses and put up a few picnic tables, a tot lot and there was an open part near one end where you could play Frisbee, soccer or throw a ball around.
I showed up here the first time with my F2 and the sniper coil I had just started using and not long after an old guy that evidently lived in the area walked over to tell me not to bother.
He wasn't being mean, protective or defensive, he was just being friendly because he said he and several friends scoured this site in the past for a long time and he was sure that everything good that was here they already found.
He sincerely thought I would just be wasting my time.
I just thanked him and said since I do this hobby for the exercise and fresh air and I was already here with nothing better to do I would just hang around and swing a little.
Also even then I didn't believe any site was ever truly hunted out, ever, but I didn't tell him that.
That first day I found a bunch of clad that was probably dropped after that guy and his buddies hunted here, some toy cars, a few other things and sorted through a bunch of normal park trash like tabs, can slaw, foil and the like.
There was enough here and it was big enough for me to decide to come back and hit this place a few more times, grid some of areas to search better especially around the area with the old house and see what I could find.
Over the next couple weeks I came back several times and eventually found some great things.
One silver dime, an older ID bracelet with a girl's name and date etched into it, a silver ring, an old Zippo type lighter and much more clad.
I didn't dig everything but I dug the solid stuff according to my digging rules and it turned out this place was not a waste of my time but a fun area to spend my time and do this hobby.
There still might be more there still but I moved away from that state so I will never know.
Oh yea...there was one more thing that came out of this site that all those other guys somehow missed.
A 1 5/16" size Harry S. Truman inaugural stock medal made by the US mint celebrating his second term.
Not the official large size inaugural coin but a smaller version still made by the mint and sold to collectors.
Officially catalogued as Stock medal # 732.
The U.S. Mint's 8th chief engraver John Ray Sinnock who designed the Roosevelt dime did the front, after he got ill the 9th chief engraver Gilroy Roberts designed the back and it was minted in 1949.
If I would have believed this guy I would never have this cherished item in my collection today.
To this day I have never seen another hunter post on any forum about finding any kind of official inaugural medal like this large or small from any president.
Plenty of presidential tokens of all kinds yes, official mint stock medals...no.
Even now I am hunting a park that most gave up on long ago and I can tell you there is a surprising amount still coming out of this so called hunted out place.
When someone tells me not to bother with hunting any site for me that is always when I say let the games begin.