Bad Drivers and Neigh Neigh Poop

I'm not sure what got into my 2yr old today but he swung wildly from crazy tantrums to side splitting funny all day. While attempting to get his 4yr old brother to preschool, he decided to throw a terrible, raging tantrum. He would not wear shoes or a coat in the pouring rain and I finally ran him to the car without either. We recovered some on the ride to school and got brother dropped off without further events. As we started the drive home, a woman decided to make an illegal U-turn and then cut me off. I proclaimed, "You are a bad driver!" to which a voice from the back seat yells, "Bad driver! Bad driver! Beep Beep, mommy. Beep, beep." Okay, I use my horn but not that much. Oh, and to drive the point home he comments, "Neigh, neigh poop!" Here in lies the need for some explanation. I do not call other drivers unsavory things like poop. Really. I promise. Secondly, we just got a load of horse manure for the garden and in the nature of 2yr old humor, my son calls everything and everyone "neigh, neigh poop" and then commences to laughing hysterically. So is there a lesson to be learned? Remember they are watching everything and will repeat it when you least expect.