Don't worry, these are the guys who have been training for many years before hand, as most of us know here it takes a lot to time and dedication to build a good physique, so unless you start lifting in your older years you are way ahead of most people, just have a look at the ages of the my Olympia's gone by they are all older coz they have built their bodies of many many years of hard work and dedication in the gym, and even the older guys will be making some decent gains given proper diet and training.
Everyone want s a quick fix and be massive at age 21, well its just not going to happen, you might have a decent body but there is still much room for improvement if your patient and work at it..