At age 27 I did crossfit everyday, ate pretty darn close to paleo, and weighed 165 lbs. and was maybe 5% body fat. Was casually dating at this time and didn't work much more than 45 hrs./week so I had plenty of free time. Played multiple sports and really cared about being fit as it helped land hotter chicks. Typical day was wake up and go for a run, work until like 5:30, crossfit right after, go play basketball or softball after that, then hook up with some chick at like 10 PM and boot her out/leave at 11:00 so I'm in bed at the same time to get at least seven hours of sleep each night. Weekends just eliminate the work and add much more time playing sports.
At age 28 two things happened: I met my wife and blew out my knee. Couldn't maintain the cardio and stopped caring so much about looking good. My wife and I both love good food and good alcohol so my nightly workout/sports was replaced by a lot of nights out to dinner eating and drinking whatever I wanted. Slowly started to add weight.
At age 29 I took a job where the more I worked the more I got paid. The pay increase was great, but I started and have been working like 60 hrs./week minimum and the stress level greatly increased. Lifestyle didn't change much and most days have been coming home at like 8 PM and eating and drinking whatever I wanted while watching TV just so I could decompress from the day. Still work out and play sports on a regular basis, but nowhere near the amount I did and the more cardio-intensive sports like basketball and soccer were eliminated for golf. Stepped on the scale a couple weeks ago (hadn't done that in a long time) and I weighed 244 lbs. I knew I had gained a lot of weight but I had no idea how much.
Started dieting immediately after and have been trying to get my heart rate up at least once a day. Also trying to cut out alcohol as much as possible. Down six lbs. in a couple of weeks. Hoping to get back below the Mendoza line by the end of the year.