Have you ever flown a light aircraft before? If not, go and get some lessons and see whether you like it! Spending maybe $500 on a couple of hours in a plane with an instructor is absolutely worthwhile if it helps you decide whether or not to spend a lot more money in the future.
You can drop out at any point during the training, or once you've got a PPL, with the only loss being the money you've already sunk into it (for which you've gained a lot of experience). Unless you actually go and buy a plane it's trivial to just walk away from the whole industry.
Like Cloud Basher has said, it's pretty rare to find a pilot who's regretted his/her decision. It seems like a good bet that all those who were going to regret it dropped out before getting a license. On the other hand, there are a lot of pilots who are now approaching or into their 80s, and the only thing that'll stop them flying is failing a medical. They've been flying for 50+ years and still enjoy it.