"Little old man and mountaineering" joke

In answer to an advertisement for tough outdoorsy types, for a mountaineering trip, a frail, little old man appears.
The advertiser asks him, "Well, how old are you?"
The elderly fellow says, "Ninety-two, I think."
The advertiser hesitates, decides to be polite and go along. So he asks, "And are you in good health?"
The old man says, "I have such pain from my arthritis, and bursitis, and phlebitis, you wouldn't believe it."
"And have you much mountaineering experience?"
"Ach, no! I'm scared to death of heights! Such vertigo I have."
"Have you any outdoors experience at all?"
"I get outside for five minutes, and I start sneezing my head off with my allergies."
The advertiser finally begins to lose patience with the charade and bursts out, "Look, sir, I advertised for experienced mountaineers. You're quite elderly, in a lot of discomfort, you tell me you're terrified of heights, and have allergies. WHY DID YOU COME HERE?"
The little old man leans close to the other fellow, and says, confidingly, "I came to tell you, on me you shouldn't count."