If you like to be in the centre of attention, then you will probably like this joke.

There should be a river in your city. And you shouldn't be rich enough to drive a car, or you should be extreme enough to like buses, trams, or other public conveyances.

So, take a bus, better a crowded one, and when it will be crossing a bridge over the river, look out and shout "Loooook! I see dolphins!"

The effect is amazing- all people in the bus try to look out in the window to see beautiful creatures, though everyone knows that there can be no dolphins in the river!

The idea is funny and innocent, but don't forget that some people in the bus may have no sense of humor