Honestly I picked up bonsai for this reason, I work in programming and everything is so impatient and in a rush I needed something in my life that slowed me down a bit. Very few bonsai are going to do anything fast.
Most of the time if you do something major like a repot or major pruning. You will want to wait a full year before doing anything but watering and feeding. The only real solution is buying a variety and a bunch more trees. The downside being you'll realize you have 10 species of tree to learn about if you don't want to kill them all. Also I'm realizing I have 2 pots to buy that will likely be $200 a piece for a cheap one, on top of the money I spent on the trees.
Just warning you not to get the wrong idea of what you are getting into. Enjoy the slow nature, some things happen relatively fast but even then you are really talking months.