Answer: After the other members tried his challenge and failed, Terry simply strapped two one-foot tall stilts (empty metal cans he had brought with him) to his feet and walked through the doorway, touching his head on the frame as he passed through it.
Terry is a gambling man. Just the other day at a meeting of his bridge club, he challenged each of the seven members to the following: "I bet each of you, seven men, a pack of Blackjack chewing gum, that none of you can walk straight through that 6-foot 5-inch doorframe --- without stopping or jumping --- and touch the top of it with your head as you pass through it; but I bet I can. Since the tallest member of the club was six feet tall and he knew he couldn't do it, even on his tiptoes, each man decided to take Terry's bet. Terry won seven packs of Blackjack gum that day. Since he didn’t use an instant growth potion, how did he manage to win his unusual bet?