Ever since I can remember when I was younger I used to act out RPGs. When I was 8-9 years old I would take my action figures into the tub and make up RPG stories and act them out around the rim of the tub while I took a bath.

When I was a little older I would go outside and pretend that I was fighting off imaginary enemies with home-made weapons (broomstick=sword, dustpan=axe, etc.) I would even simulate having a menu and choosing my battle strategies.

After that came the phase where I would just close my eyes and imagine RPGs I was creating in my head, usually as I was going to sleep. I still do this on occasion.