It’s just way too easy to mess with drunk people.
Once when Torben went to a formal dance, Jan came along. We were wearing reasonably identical tuxedos and the biggest difference was that Torben had a blue bowtie and hankerchief while Jan’s were red. It was great fun already, and then someone starts the twin questions; we just answer and have fun.
We meet one of these people on a staircase later on, and he’s gotten pretty drunk. He stops us and chats with us, and we convince him that he’s seeing double and that he’s only talking to one person who isn’t even a twin.
We overheard him telling this to someone else afterward. It sounded like he believed it.
Torben was working in Japan for a few years and Jan visited him. One morning Torben took Jan along to work, and while some of the people there knew he was a twin, most didn’t. To the Japanese, all “Westerners” look the same – much like the reverse – but people were still very surprised to see two copies standing there. Even better, Jan was wearing Torben’s ID badge and was introducing Torben as the visitor, and they didn’t catch on.
Inevitably, someone asked if we had ever done pranks and we started explaining that we’d share one job and nobody knew, so because today is Tuesday it would be Jan working today and Torben gets the day off. “But it’s Wednesday,” somebody said. Jan quickly improvised and said “Great! Here’s the badge and that’s your desk” and then he left! (Of course; he was heading out sightseeing after this office visit anyway.)
The coworkers and managers stared at Torben while he just looked a little forlorn, shrugged, and sat down to start the day’s work. They were seriously worried that Jan just left Torben to do his work, and Torben played along for as long as he could. People got increasingly exasperated and after several minutes Torben burst the bubble. For several weeks after that, his Japanese boss repeatedly asked who he was.
Another time Torben arrived before Jan had finished his work, Torben went to Jan’s office and found him seated on a sofa, chatting with his boss in a chair across the room. Since the door was open and they were obviously in a casual conversation, Torben just waved to Jan and leaned on the door frame, waiting. Eventually his boss noticed Torben and continued his conversation with him, oblivious of his switch. He noticed Jan in the sofa and continued his conversation with him, again just as oblivious. After switching back and forth way too many times (was he even _thinking_?) he suddenly stopped mid-sentence while his eyes jumped from Jan to Torben and back again several times.
We burst out laughing and Torben was introduced to Jan’s boss. After that incident, he frequently asked Jan how he could be sure it was really him.
Another story from Torben’s office: One girl seemed unable to mentally process the fact that twins can exist. She liked Torben just fine but when Jan stood next to him, she literally ran away because the concept of twins scared her to pieces. She told Torben it was “extremely spooky” to see him twice at once. That happened every time she encountered both of us, but never when she met only Torben.
The best stories always happened when one of us was picking up the other from work.
One day at work, Torben remembered that Jan was going to pick him up from work at 5pm – it was just a few minutes before 5 so he called the reception to expect the guest (because guests had to ring a bell and couldn’t just walk in). He heard the receptionist pick up her phone but she didn’t say anything even after he prompted her a few times. So he put down his phone and walked to the entrance where he found her frozen, staring at the (still closed) glass door where Jan was waving. Apparently Torben had called her just when Jan rang the bell, and her mind had imploded because of the impossibility. Torben let Jan in and introduced him to the receptionist. “Flabbergasted” is probably the most appropriate word here.
The next day, the office assistant sternly told Torben off for being “mean” and he could not convince her that we didn’t plan that incredibly amazing timing. She never forgave him… but these things just happen.