The Tractor and the Farmer's Son

It starts off with a farmer having a young son who is really really interested in tractors.

For his 3rd birthday his father takes him to a tractor show and the boy loves it, he can't get enough of it.
For his 10th birthday his father lets him ride with him on his tractor, again the son is loving tractors, can't get enough of them.
For his 17th birthday the father buys his son a tractor and the son is loving it. For 10 hours, he is riding up and down on his tractor all day at the farm, just before he is about to come home he hits a mound and the tractor flips and falls on top of the son. He was stuck there for 8 hours in the rain before his dad rescued him.

After this he absolutely hates tractors, can't stand them.

So a few months later he is walking down the streets and there is a house on fire and a woman screaming "my baby, save my baby"!
The guy runs up to the door, breathes in and inhales all the smoke and the fire goes out, he runs up saves the baby and brings the baby back to his mum.

The woman thanks him over and over again and asks how did you do it?
The son says:"Oh, it's nothing, I'm an ex tractor fan".