"Spare a little change for a crazy old man?" But he's middle-aged, not old, and what's crazy about him isn't immediately clear.
Let's ask him, then.
"What's so crazy about you, hey?"
Taken aback, or maybe better to say, stunned speechless. "Um, ok, well... I'm too old to be doing this?"
"You're not that old." And, let's be frank, you're disappointingly uncreative. Give him some change, continue on.