Anyone who has children will be well aware that not everyone can do it. Young children just don't understand the concept, and parents are forced to endure endless knock-knock jokes that don't make sense. I don't remember inflicting my mum with lots of tales about rain being the result of sad clouds. Sorry about that.
Once we grow up, we do recognise what makes a joke funny, but just because we know what makes a good joke, doesn't necessarily mean we can tell a good joke.
Although I think the ability to make someone laugh is a natural gift, that doesn't mean joke-telling can't be learnt. There are several factors involved, and the most important is timing.
If you have gift and want to develop it further, The Museum of Comedy is running an eight-week course from the 25th September. You will start off learning the basic principles of comedy, and then begin to hone in on your area of interest, whether it be sketches, character monologues, stand up routines, or the written word. Classes will be held every Thursday from 7pm - 10pm until 13th November.