Sounds like the way people with ADD tend to pick things up, get really into them for a short period of time and then put them down. Or kids when they are searching for their “thing”, maybe the guys you know are just big kids who still never found their thing. Or maybe its just more noticeable than the people who pick up something new, get really into it, and do stick with it forever, which is also something that happens. I know guys who got super into grilling or woodworking or whatever and are still at it after many years.