I changed my life, or rather God did, in my mid-thirties, so I can't compare my life to others. A book that my wife gave me at that same time also changed my life: "The Miracle of Fasting" by Paul C. Bragg. Something he said in the book regarding adherents to his health method resounds with me to this day.
"You will see your loved ones and friends sicken and die before their time."
This has been true among my family and friends. They couldn't or wouldn't overcome the habits that were slowly killing them before their time. I believe this is true of most people as well.