I do think that if the OP has had to make a concerted effort to lose weight at 22, then it is possibly slightly misguided to be, effectively, preaching at a wide range of ages as to how easy it is to lose weight and maintain that loss.
You can only preach on the ability to maintain weight-loss once you've actually, you know, maintained it for any decent length of time.
However, getting older is not necessarily a guaranteed pitfall when it comes to weight loss, and I don't really understand why some people are basically saying that is is.
I spent my teens being slim as anything through eating healthily and naturally (thanks to my Mum). However when I moved away to university and was living as a dirt poor student I got into some terrible habits. My weight yo-yo'd right through my 20s and most of my 30s, with most of my time spent round the size 16 mark. At 5"10' I was abe to carry it reasonably well, but there was no denying I was solidly built.
However, it's been since having children that I managed to get my weight down and maintain it. I turned 40 last month and have been a size 10 for a year now, and hope/expect to maintain that, via nothing more or less than 'simply' eating less overall than I used to (5:2). I used to eat quite a bit more than I needed to, and so inevitably gained weight. Now I eat less than that. Still enough to enjoy life, and absolutely NO cutting out entire food groups, either.
Getting older (and yes, I realise I have a lot of getting older yet to do), having children, going through the menopause, etc, are not all necessarily downward spirals into weight gain. They're just not.
Menopause is not a new thing. A couple of generations ago, many post-menopausal women remained slim.