12-15 pounds already is tremendous progress. It is also something different when you are lifting weights and you may not be losing weight but you are getting stronger. I was talking to a friend today about this. I weigh 242 pounds right now and most people would look at me and think I'm a fat ass. But I can deadlift over 400 pounds and do 2 pull ups. 2 pull ups isn't "in shape" but I know a lot of people who would think they are in better shape than me that wouldn't have the strength to do 1 pull up. Someday I hope to be able to do more than 20-30 pull ups or more. I may be fat still, but I'm stronger than I was, and in better shape than anyone expects. It is almost like having the ****box car with the V8 powerplant hidden under the hood - everyone thinks it is slow and a beater and can't do anything, but they have no idea. I can move furniture, go up stairs, run, you name it, without getting winded like I used to, extra weight or not. That is what is really important to me. The looks are nice, but secondary.
To me, it's funny too. I always thought that the things like not being able to wear normal clothes, or not fitting in a chair, or whatever would be more immediate and more painful and cause the change. I guess being a little older, the pain was easily buried and not as prevalent as if I was in school being made fun of by other kids - but I started to change when I saw that my grandmother could no longer walk because of her bad knees. Then it occurred to me that the doctors would not operate on her, not because she was 85, but because she was so out of shape and wouldn't recover. Then it occurred to me that my dad is 20 years younger and losing his ability to walk because of bad knees. Then I realized, they are both doing this to themselves. My grandmother has very little chance of turning it around (although maybe not totally impossible), my dad still has a chance but it will be hard, and I am on that same path - but it is a lot easier to change now then later. This changed my thinking from "drop 100 pounds in the next 6 months" to realizing that most people gain 5 pounds/year and over 5-10 years they wake up one day and they are 50 pounds heavier. If I changed that to losing 5-10 pounds/year, I'd wake up at 44 and weigh 100 pounds less than I do now. That would be a simple change for me.
During this process I have also realized that some people have different "mental" proclivities. I would rather bust my ass, work harder than anyone thinks is possible, and collapse in 10-15 minutes knowing I kicked my own butt, while some other people would rather workout for an hour, with a slightly lesser intensity and more volume. If I suddenly tried to workout for hours on end, I would hate it. If I lowered my intensity I would feel unchallenged. If I did 20 reps on everything, I would hate the pain that causes. Others who like high reps probably would hate the drop sets and pain caused by my way of training. I hate running, others may hate weights and love running.
The same thing applies for diet - I may eat 4-5 times/day and others may find that they naturally do an intermittent fast every day.
I think noticing these tenancies is important - it can help you to make the smallest adjustments possible that will get results. If someone normally eats 2 meals a day, going to an intermittent fasting setup might be almost unnoticeable - while going to 6 meals a day will seem like a big change and a chore. I think noticing people's tendencies and adjusting the small stuff can make the change easier.