We do not know where he got the idea...but somehow Elias has determined that anything with wheels is a tractor. Trucks, cars, trains, lawn mowers, strollers, etc. Tractor came shortly after uh-oh and Da-Da. Give him a "tractor" and he will be entertained for hours. This, combined with going outside, is his current picture of heaven. Reminds me of Yaconelli's Dangerous Wonder.