The Hitchhiker's Guide to the Galaxy
has this to say on the subject of flying.
There is and art, it says, or, rather, a knack to flying.
The knack lies in learning how to throw yourself at the ground and miss.
Pick a nice day, it suggests, and try it.
The first part is easy.
All it requires is simply the ability to throw yourself forward with all your weight, and the willingness not to mind that it's going to hurt.
That is, it's going to hurt if you fail to miss the ground.
Most people fail to miss the ground, and if they are really trying properly, the likelihood is that they will fail to miss it fairly hard.
Clearly, it is this second part, the missing, which presents the difficulties.
One problem is that you have to miss the ground accidentally. It's no good deliberately intending to miss the ground because you won't. You have to have your attention suddenly distracted by something else when you're halfway there, so that you are no longer thinking about falling, or about the ground, or about how much it's going to hurt if you fail to miss it.