When did you "know" you were a car guy?

as long as I can remember. One of my first memories must have been around 1970 I was ten and being raised by my grandfather, in the back of an old pole building was an drag saw I kept telling my grandfather we needed to build a go kart using that motor he would just smile, and then about the 10th time I mentioned it he said if you get the motor running we will work on a go-kart. It was summer and I was out of school about a week later as he pulled in the driveway from work I pulled the Rope start and to his surprise fired that old motor up. Something about the sound of that straight pipe and the feel of the rumble of that motor gave me a feeling inside like none other and thank God it's still there.