im 28 and have went every other year or so since i turned 20. i think its really important to go to the doctor regular as soon as your and adult. its good piece of mind after you get tests done and know your good to go and have life in front of you. plus its better to catch things happening to your body in the early stages if any than wait until they get out of control which they can if it develops of the years
seriously though once you hit like 25 you are just living to die. it seems once you hit that point you are more prone to death by disease or accident because you are now officially living kinda long so why not get urself checked. i dont get the people afraid to get checked just do it its and hour outta ur time and once its done your happy`