Its something I see written or hear being said that having children helps keep you young, teenages in your 40's and 50's keeps you youthful but in my experiance my teens make me feel ancient. I was wearing my granny boot slippers (very toasty) and big cosy dressing gown as I shuffled into the kitchen this morning half asleep for my coffee and DS 14 said "oh look hagrids up" Which made DD16 laugh. I the caught my reflection in the fridge door and could see what they meant! Yes it was funny but sometimes I feel so ancient when I see myself though their eyes. Sure I could make an effort before leaving the bedroom each moring but why should I in my own home? I suppose everyone my age (44) looks a little rough. My childfree friends probably look crap at times but they can do it in private and when at large they look as svelte and cool as they did at 25! They also don't spend their life slaving after three kids so have more time and money to spend on themselves, attend concerts, galleries and eat out at new resturants (ok perhaps not right now but generally).
I love my kids and am happy with the choices I made but the idea that they keep you young is a total myth in my opinion!