I've got three major routes to choose from, between 7.5 and 10 miles in length. In addition, there are 4 or 5 crossroads that can link me between each of the three major routes.

In other words, I've got about a billion routes to choose from!

Even more if you consider doubling back. Sometimes I'll start home on one route, then cut over to another and ride back to work - then finish by riding the third route all the way home. No repetition, and it makes the ride much longer and more interesting.

FWIW, I had been going the same exact route to and from work each day for a loooong time, and did get a little bored. Then I had the revelation that if I got bored, it was only because I was stupid enough to take the same route instead of exploring alternates.