In the beginning, you might laugh together about all the ways in which your perspectives and philosophies differ. But as your friendship develops, these differences could become a real problem, and you could cause a rift between you and your friend if you aren't careful in how you treat them. Whenever your buddy has a brilliant idea, you'll quickly yank them back to reality, exposing the flaws in their logic and the practical reasons why the idea just won't work.
You'll think you're helping them, and you may be right -- they could be a real dreamer. But dreams, hope, faith, inspiration -- all of these are essential complements to reality, practicality and sober thinking, and your insistence on the latter will make your buddy feel inhibited. If this friendship is to last, you'll both have to learn to live with the other's perspective.