And part of it is just innate ability: he sometimes seizes a coin in the parking lot that everyone in the family has already stepped over -- and he's the only one to see it!
We recently got home from a trip to Seattle, and he found 63c(U.S.) on the trip home: a quarter, two dimes, two nickels, and eight pennies.
His brother, B2, found 16c(U.S.): a dime, an nickel, and a penny.
The day after we got home, the kids ran some errands with The Lady (I stayed home to unpack and catch up on the laundry). Blondie Boy found a 10c piece, a NZ 20c piece, and a $2 coin.
Blondie Boy and The Girl also saw a 5c piece a the same time, but since The Girl wasn't able to go after it because The Lady had asked her to watch the shopping cart -- so Blondie Boy got it. But because The Girl wasn't able to go after it, The Lady had Blondie Boy give the coin to The Girl.
Then, B2 felt bad that he hadn't found any coins, so Blondie Boy promised the next coin he found would go to B2. The next coin turned out to be another $2 coin -- which Blondie Boy willingly gave to B2.
So, in the last 32(?) hours, Blondie Boy found (but didn't necessarily keep) about AU$4.35 (if you pretend $AU=$NZ), plus the earlier US$0.63.
And, during the previous three weeks (i.e. our trip to Seattle), but excluding the trip back, Blondie Boy found 63 coins: a 10 florint piece (??!!), 2 quarters, 7 dimes, 7 nickels, and 46 pennies.