they're hard to grow due to the tiny amount of soil they have. you're basically stunting the tree by giving it juuuust enough water to hang on. this is why forgetting to water is so disastrous. they require almost daily care/training/shaping, but they're sooo cool. I trained a couple (pines) and bought a maple bonsai when I was in high school. I gave them to an older friend in town who taught me everything I know about horticulture (friend of my grandparents', had a stroke, I helped him out at his wholesale propagation nursery through high school) when I went to college. he died, and his wife still has the maple.
i am really thinking in growing my own bonsai tree 
