I have worked at a "startup" for 6 years where I have been, primarily, the only developer. It has been extremely taxing to say the least. I started in my early thirties. Sometimes I feel like a fool. Sometimes I worry about what I will do next. I do hope to never again have this similar experience of being the only one doing all of the truly hard (and it is hard) labor of creating a system when the reward is little more than a paycheck. I wasn't a founder, but I often think that the workload I have received is nothing short of one.

If anything, I think it isn't the experience of a startup that is terrible so much as the emotional burnout that often seems to result from being in one. I think everybody in their youth should experience it just to see how far they can go. I would only recommend that they don't do it in a situation where they are the only one steering the ship :) It can lead to lots of sleepless nights and tremendous amounts of pressure, but I would imagine that sharing the load with a couple other people would make it a lot more "fun" as well as providing all of the educational benefits available for participating. Nothing is better for developing your style as a programmer than having to program a lot over a long period of time. There are more opportunities to make mistakes in a startup which means there are more opportunities to learn. I would say it is far better than a corporate environment, which I have also had the pleasure of working in.