I started with one cheap tree from a nursery and killed it within three months. The second one lasted a year, and the third is still on my desk.
Bonsai teaches patience in a way nothing else has. You make a cut today and you only see the result next season.
The basics are simple: good light, careful watering, and the discipline to prune a little at a time instead of all at once.
It is the slowest hobby I have, and the one that calms me down the most.