At-home trail riding

Why is it that I'm more nervous about riding at home than I am in other places? My husband and I took our greenest horses out yesterday for about a 1.5 hour trail ride around the place. Tex jumped and crowhopped a couple times when the two dogs ran up behind him- once on the trail and once in the pasture.
We rode on trails, up and down a few hills, and in wide open hay fields. In one of the hay fields, I asked Tex to lope off in a circle, and he threw a little fit. After a few more circles and asking him to move in and out of the circle at a lope, he was sweating like crazy and had no more energy to be stupid.
The rest of the ride was peaceful.
TM