Most missed memory from childhood

Mine would definitely have to be my imagination. When I was a kid, for years my brother and I entertained ourselves all day long building legos and having huge lego wars, building huge castles, or we'd go outside and play some of the craziest games. For the life of me I can't remember how to have an imagination like that. When I hit about 13 I decided that I was to grown up to play legos or any of those 'stupid kid games', so I blocked them all from myself and just spent time reading and other hanging out at friends houses playing video games. If only I'd known the disservice I was doing to myself :o(