This really happened to me, and I was pleased to solve the riddle in real time:
Context: There is a house with two family members. A father with a bad back, and a mother who is watching her favourite TV show in the bedroom. The father realizes that one of the three light bulbs of the living room chandelier has to be replaced. Since he cannot find the ladder, foolish dad moves a table to the centre of the room, puts a chair on top of the table, and then, new bulb in hand, climbs up on top of the chair. He can only just reach the chandelier, but.....OH NO! All bulbs look the same! He has forgotten which bulb needed to be changed. Whats´s his best option ?
1. Call his wife to have her switch on the chandelier lights.
2. Climb back down, switch on the lights, memorize the dead bulb and climb back up.
3. Change any one bulb, then climb back down and hope to be lucky.
4. Any other idea?
Maybe it´s too simple a riddle, but try to find the answer while you keep your balance up o that chair!