When you talk "classic" to me that means actually Classic. Not just funny. Gags you may have to wait a lifetime to play. Just can't be done until the circumstances present themselves naturally. You can't set them up. Here's some I certainly didn't invent - just was ready when the time came:

At the Blairgowrie Fest about 1967, I being a bit tipped (as was everyone else) has to find a tie-down for the tent. Searching far & wide I finally found a 6-foot cord. The effort being exhausting, I hadn't the strength left to carry it so I struggled to drag it along the ground. Says Roy Williamson, "Hey, Abby, why are you dragging that string?" I with befitting dignity explained: "Hey, man, you ever try pushing a string?"

Don't look like much typed but it was sure right then. I'm proud that in my time I've also had the opportunity to (appropriately) say "This size, please" and also "Quick, get some water."

My life is thus fulfilled but I have a couple of others in mind just in case the situation arises...