1. He’s impossible to be with – spoiled, mama’s boy, still lives in the parents’ basement, or a jerk, 2. Gay and in the closet, 3. Celibate and not interested in relationships, 4. Not ready for committment – hasn’t found the “right one” yet, or 5. Is growing up slowly in that way that guys do nowadays, where they extend the college mentality as long as possible. They don’t want responsibility because it’s a bummer, they don’t need a wife because they have many short-term girlfriends that put out just fine, and they really don’t have that much of a career yet because they took ten years to get that bachelor’s degree. Maybe he still drinks with his old college pals on Friday nights? This kind of aimlessness in life with no real reason to change is what’s making 30 the new 20.