Plain Stupid
One day Mike and John were watching T.V when the news came on, showing a man standing on a bridge about to commit suicide, suddenly Mike said "I'll bet $10 that the guy won't jump off", John said I bet $10 that he will jump. Unfortunately for Mike the man jumped off the bridge, Mike accepted his fate and stretched forth the money but John didn't take it, saying "I can't take the money because I cheated, I already saw the news this morning" but Mike insisted and said "no you can take it, I cheated too, I also watched the news this morning, I just didn't know the guy will be silly enough to jump again!