Had the same brown bob for 20 odd years, with the odd longer version or short hair. It's now below my chin and fairly thick and wavy so needs straightening. I also have a lot of grey hair so I dye it a lot, condition is ok and because it's thick, it can hide grey roots.
I have a hankering to get my hair cut short (friend tells me it suits me) but worried it will age me and that grey roots will show more quickly. Is it middle aged? I always knew I would go short eventually but the trend seems to be to keep your hair as long as you can to look younger.
My sister had fantastic cropped hair in her late 30s which really suited her, but she has grown it long now and it makes her much older looking (she is 42 now) - it just drags down her whole face. So short hair doesn't necessarily make you look older! But it needs to be a very good cut (part of the reason my sister grew hers is that she couldn't make it to her very good hairstylist every 6 weeks after she moved).
I had my bobbed hair cut around 45-ish and kept it that way for almost 10 years. It was a kind of Princess Di cut. Then I decided to grow it out and it's now almost shoulder length , at 58, though still with some long layers and a soft fringe. Everyone says I look much younger with it longer. I look back on my short hair with horror- one reason is I have 'nice hair' according to hairdresser- fine but lots of it-and short didn't do it justice. I wouldn't go back to short.