Isn't this the same guy who got shipwrecked in our wading pool?
A man who gets lost in a sandbox as if he were stranded in the desert, as depicted, is not so bright because it's difficult to put oneself in a dire situation within a benign children's play area. The kids refer to another analogous situation when the same man put himself in a dire situation (shipwreck) within a benign children's play area (wading pool).