People are living longer now, attitudes have changed too. I remember my mother telling me that when she turned 40, she felt her life was mostly gone and she should sit in a corner from then on, in a twinset and pearls. That was how it was then - in the late 1940s/50s - then the youth era of the sixties came and it all changed. None of us in our sixties or older think we're old (well, I don't) - my mum lived to 94 so if that's my yardstick, I hope I've still got a third of my life still to come.
If you look at photos of post-war young men and women, they all dressed like older people, all very much of the same mould. You don't see that today. Medicine and healthcare has improved so we live longer, generally are better off than our grandparents, and want to live interesting lives - that keeps us younger in spirit!