I have a knack for seeing change everywhere. My spouse jokes that it's a superpower (or to reference Seinfeld, "You’re eating onions, you’re spotting dimes, I don’t know what the heck's going on!")
Also stopped at a stop sign one day to see a $5 bill by the curb-- I absolutely jumped out to get it. Usually find coins in parking lots though. We've also found a nickle from the 1920s which might increase in value some day. Combined with the change from cash spending, we've got around $25 already saved up for 2019.