Like @ms.sss I too lost more than my original goal because it took a while for me to work out the calories I needed to maintain. That is the number of calories my body needs to function. Eat fewer calories, you lose weight. Eat more than your body needs, you’ll gain. I slowly increased the calories I was eating as I was physically able until I reached the number of calories I needed to maintain.
I lost another 11odd kilos over a year after goal. Been happily sitting at about that weight (+/- 1kg) for about 9months. But I’m really still a newbie. Time will tell. I do have wriggle room if I do succumb to the 5 odd kilo rebound gain in years 2 or 3.
Even though my BMI is on the lower end at around 18.7, I’m certainly not bony nor look undernourished. Honestly, you can look a little drawn when you get near your goal but it all seems to settle after a couple of months. Eating a little more: a few more carbs, vegetables, fruit, etc. all helps. A year ago, my uncle very kindly (not!) told my mother I looked like death. Now he tells me how great I look. As for looking older. I don’t think I do. Most importantly, I can actually see my real face now: cheekbones, jawline, eyes, etc. because there’s no fat distorting it shape.
You may meet your goal, you may not or you may exceed it. Age, genetics, weight loss history, metabolic rate, etc. influence how much weight we can lose after surgery. But let’s be honest (some straight talking coming), in the end we control what we put in our mouths & that is the biggest influence on our weight.
I think your weight is individual. Not just a number on a scale or a number you’re ‘supposed’ to be but how you feel in your own skin. Happy, healthy & enjoying life.