I have no abs, but surprisingly big shoulder muscles and triceps for my size, and physical fitness.

Like my entire body is underdeveloped, but my triceps and shoulders have always been naturally big. I have normal biceps, but massive V-shaped triceps. And on my shoulders, my trapezius muscles are also above average developed for someone who barely works out. It's legit like a bump, even at rest.

On my back same story, my back in general is not muscular, but I have visible lats that stick out. Even more when I flex them.

I used to be rather muscular in my late teens due to heavily working out, but I stopped and haven't really been lifting weights for years, and switched over to doing mostly cardio, like running and cycling. So I lost most of my gained muscle mass, with exceptions of my traps, lats and triceps. Don't know why exactly I retained those particular parts.