This feeling was no doubt made more acute by the fact that, when I first moved from my previous abode, I returned every weekday to attend the school across from my former home. After school, once I'd had my tea, I would visit pals in the area and, truth to tell, I was along there so often that it probably never quite registered that I no longer lived there and was merely a visitor.
The distance between the two neighbourhoods seemed practically non-existent back then, and, to me, was no greater walk than the local shops at the end of my street. It was the same with most locales I was familiar with - they seemed no farther away than the time it took me to think of them. My house was like the TARDIS - outside its doors was any location I wanted to visit. All I had to do was walk through them and I'd be there.
Nowadays my perceptions are strangely different. My old neighbourhood seems as distant as MORDOR, and a lifetime away to reach. What was once a brief walk now stretches before me like an arduous trek from which I may not return. Whereas I never before felt far removed from any familiar childhood place, I now feel remote and isolated from them, and they seem to be as difficult to reach as the fabled BRIGADOON.
I suppose that's as good a definition of 'over the hill' as it's possible to get. Funny how I never before realized how literal a description of advancing years it actually is. When you're over the hill, once-familiar 'places' on the other side are far more difficult to access - and it's an uphill struggle to even attempt the task.
"Ah, sweet boyhood, how eager are we as boys to be quit
of thee, with what regret do we look back on thee before our
man's race is half-way run!"
J. Meade Falkner.