I'm doing 2 gap years, spent the first half of this one working in a bank and then in January went to Thailand for 5 months, trained as a professional scuba diver and am off tomorrow to work in diving for about 4 months in Greece... I've got a lot of ideas in the pipeline for my next adventures before uni in 2008 (or 2009...) and beyond.
I kinda thought a bit like you... at what other point in my life am I going to have so little responsibility where I can go and travel around the world and live the dream? Life's too short to just do what you think you should be doing rather than what you actually want to... If you want to do two gap years, then do it. =D In my adventures I met people who were twice my age and doing what I was and they were jealous because they wished they were where I am right now.
You only live one life, may as well live it, innit.
p.s. I love South East Asia... I left my heart out there.