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.