Fun topic!
I built my first model - a Strohmobile - with my uncle Jim as a 5/6 year old when he was staying with us one winter. I was allowed to help him and after that he, and my parents, kept me in the hobby with snap kits. As I got older, I was given glue kits that were turned into assembled glue bombs. I quit about age 8 and started playing with GI Joe's instead of jet plane models.
Age 14 - GOT MY FIRST AIRBRUSH FOR CHRISTMAS! Back in the hobby again for 2 years before girls, school, girls, a flood, college, marriage, and a newborn son took over my life.
Age 28 - my parents replaced my airbrush and compressor that I lost in the flood of 1997, and I've been back in the hobby for the last 3 years and will never quit!!!!! 8)