Why doesn't my neck crack anymore?

Question

When I was a teenager, I used to be able to crack my neck pretty much on command. Now that I'm in my twenties, I can never do it no matter how stiff I am. It was only amusing before and I don't really have a desire to do it, I'm just curious about why I can't do it anymore. Also, I didn't used to be able to crack my back, but since I've been doing back strengthening exercises at my gym, it happens all the time? Why now and not before? Why can't I crack now when I could before?

Answer 1

its just a part of growing I guess. I would see a chiropractor if you want your neck or back cracked properly, it feels amazing. Just be sure to do alot of stretching before workouts.  

Answer 2

because ur body grows and develops changing the characteristics of your skeleton.