That is a really hard question and people have spent their lives studying and thinking of this. And guess what? They are no closer to an answer than when they started out.
But there are some very insightful things about infinity that really make this world and our idea of existence interesting, to me anyway. Here is a brief-ish introduction of infinity from Gizmodo. They do a really good job of presenting the problems that infinity presents. That is, once you start thinking of it too much, you might very well go mad or get a splitting headache. Never mind though, you can read their introduction, even if you think know what infinity it, there is some really good information and illustrative examples of different kinds of infinities.
Yes, you read that correctly. There are different types of infinities. Infinity by itself is trouble enough. Infinity-of-infinities is well, infinitely more troublesome. Hence, why I believe that infinite as an idea is fine, but in any practical sense is just a figment of our imagination, if we are real. If infinity is real, if the universe is indeed infinite, then we are not real, but rather a simulation, hence making it possibly to render an infinite entity (timeline, number, world, etc.). In a simulation, I can driver forever, if that simulation is given enough rules to generate more road and artifacts.
So that is my crazy idea, we are a simulation if there are infinite anything.