Just had to add my two cents. I took TKD instruction from 7 until I was 13 (BB 1 DAN), then I left and went to study Shotokan, where even with all of my TKD skills it still took me 5 full years to reach BB. IMO Shotokan was a lot harder, but then again my Sensei was very orthodox and old school, he did not believe in MA as a business. You had to earn your rank.
Then the whole life, marriage/kids thing kicked in and I practiced less and less. Now I am just a 48 year old man that reminisces from time to time. But one thing is true. MA helped mold me into the person I have become today. Nowadays, I could not do a dolrya chagi or a Mawashi-geri to save my life. But then again, now a days I have a .40 caliber Glock 23 to keep me from harm