I had wanted a juniper bonsai for so long, and was really excited when the plant nursery down the street from me got a large collection of them. I went and picked out a fairly young bonsai, but they had some that were older than 80 years and amazing looking (not to mention incredibly expensive).
Mine died, and I figured I had killed it, even after sticking to the directions at closely as possible. When I went back to ask them what I did wrong, turns out it wasnt my fault. ALL of the bonsais they had there had died just due to the climate.
Im planning on just making a fake one some day =P