Start? When you put it like that it makes me think I never started. I was always roleplaying. I was a soldier on the playground, I was a trader in my friends shed, I was a superhero as I walked out of class, I was a starship captain as I sat on the bog.
All RPGs did was add the Gaming, the rolling of dice, the determining success. And all that stuff I did as a kid. I still do it now, even when I am not gaming.