I'm Honestly Curious

I have a question that rattles around in my brain a lot, but first, a workout!  This morning I was feeling in the mood to spare my lower body a bit (in light of a long trail run tomorrow morning), so weight lifting focused on upper body.  I decided which exercises to do on the drive to the gym.

Kettlebell swings: 20 @ 15 lbs, 20 @ 20 lbs
Pull-ups, 30 lb assist: 5, 4 reps
Push-ups: 7, 6 reps
Upright cable row, set to 12: 11, 12 reps
Weighted ball crunch, 5 lbs: 17, 17 reps
Farmer's walk: 70 lbs x 2 reps
Alternating military press, 40 lbs: 10 reps (each side) x 2
T & Ws (basically a rotator cuff/upper back move), 10 lbs: 10 reps each exercise x 2
Then 16 minutes bicycling intervals, and a little stretching to finish.

To lead up to my question, there's a little bit of background information.  I am a believer, proponent, activist, etc. in HAES--health at every size.  I believe someone can be of any body shape and be fit and healthy by engaging in healthy, fitness-promoting activities like nutritious intuitive eating and enjoying movement.  I also believe that discrimination based on size and fat-shaming are odious things that should be squashed out of our society.  Everyone deserves the right to live free and happy in whatever body they currently have.

One of the statistics put forward frequently in many of the body positivity blogs I follow is that only 5% (or 7%, or less than 5%, depending on the source, but somewhere in this range) of people have long-term success in keeping weight off after a diet.  Back when I was a teenager (14, 15 years old or so), I remember the scale reading upwards of  185-190 lbs.  Then, during my junior and senior years of high school, I started exercising more--going for walks and jogs around the track--and keeping track of my eating.  By the time I headed off to college, I weighed around 150 lbs, and have been at 150 plus or minus 5 pounds ever since.  So I lost 20% of my body weight and have kept it off for nearly 20 years.

Does this include me in the 5%, or were there special circumstances because I was a teenager at the time?  Was I just young enough to establish a new weight set point, compared to people who try to lose weight as adults?

What I think really made the difference for me is that, at this point, I wasn't heavily influenced by anything other than my high school health class.  I did things like just eating lower-fat, giving up first red meat then becoming a vegetarian with a varied diet, trying to eat my fruits and veggies.  While I kept a detailed food diary, I didn't really have a calorie goal for the day.  Some days it was around 1800, some days 1600, and some days 2000.  I was still getting the calories and nutrition I needed to sustain my body, at just enough of a deficit to lose some extra fat.  And it was a lifestyle change; I curtailed the junk food and learned to enjoy the pleasures of movement, and have never gone back to my childhood habits.