The question came to me because I wanted to share the story of a prank I kind of slithered into quite on accident.
A week ago I threw a party and invited quite a few people from my old school, and it was all around enjoyable. We don't have these type of parties to often, so whenever they happen it's quite lively and people joke around that they almost couldn't recognize each other anymore, etc. etc.
One of the reasons why I had invited so many people (I normally try to host as few and small parties as possible, because I hade cleaning up afterwards) was that I had decided to completely switch the style of several rooms in my apartment, the furniture already waiting in my garage. So since I had to basically throw out all of my old furniture and clean up all rooms anyway, I thought that it couldn't hurt to host this particular party.
Enter Daniela, one of the guests. The day after the party I receive a call by her, telling me she must have left her iPhone on the living room table and whether she could come over to get it back.
In a moment of absolute brilliance I said that I was busy today, but that she could come over tomorrow evening, since I'd be able to leave work early. She agrees, and as soon as she hangs up I start to go to work. I find her iPhone, store it somewhere safe, throw out all furniture, clean up the rooms, paint the walls, bring in the new furniture, make everything look presentable and then finally place her iPhone back on the new living room table.
All of that took me a bit more than a day, so I was finished around noon of the day she said she would come over, meaning I still had a bit of time left.
And since I had nothing better to do, I decided to top it all by calling over a friend from university, who I knew Daniela wouldn't recognize (two different circles of friends - I don't mix my friends, I throw parties for the friends from my old school and my friends from university, but never both at the same time).
Thus began the impromptu coaching, where I told him a bit about Daniela and what I knew about her.
About two hours after my friend had arrived Daniela ringed at the door - only to have some random guy in my clothes open the door for her, invite her in into an apartment that looked nothing like two days before and hand her her iPhone from the table in the living room. He didn't even have to use much of the knowledge I had instilled on him, she was so completely confused that she didn't ask many questions.
Opportunities like this happen waaaay to seldom not to act on them.