I whole heartedly believe that the body is meant to move, be challenged, and to enjoy it. Physical culture to me means finding the active modality that fits your personality the best and running with it. It means prioritizing movement, from walking to your coworker's cube rather than emailing, to riding your bike to the store rather than driving, from the "normal" way out.
I'm not talking about exercise, I'm talking about activity. DOING things, with your BODY.
I can't say I've met anyone who has told me they aspire to be couch potatoes.
But you have to get out there. You have to prioritize activity and you have to prioritize trying new things to find that niche.
Humans are very much creatures of habit. You go into any college class room and you'll notice that student tend to sit in the same area, if not the same seat, for a class through the entire semester. We make our friends and we stick with them. We rarely up and move to cities that are really far from where we grew up by pure choice, it's usually because of work or school.
You'll have to make a very active decision to get something new into your routine. You're going to have to step out of your comfort zone and decide that your past experiences aren't adding up to what you want your story to entail.
It's not easy, but each time you set an appointment, and KEEP it, trying new things becomes easier and easier. Trying new things becomes a habit in itself.
I want to make a point to myself to try something new each month. That doesn't mean everything will become a new hobby, I'm sure most of the things I try will be "Oh, that's cool. Moving on."
Make a goal like that for yourself. Never stop exploring.