I still live in the same community where I grew up. Back in my young days, in the late 1980's and early 1990's, there were many mercury vapour streetlights and ballast-in-arm units, as well as privately owned NEMA units. I don't remember days before HPS, however. Then in the early 1990's, the power company had a HPS drive and most mercury vapour units in power poles were replaced with HPS, although a fair number of mercury vapour remained. Nowadays, very few HPS remain, the majority being replaced with LED or removed altogether if the customer requested end of service.

When driving around the community, sometimes I look at power poles at specific locations and think of the mercury vapour fixture that used to be there. Sometimes, there is a HPS or a LED fixture there, sometimes just the remains such as a former wire connection or a through bolt that was never removed. Do any of you do this when driving around a familiar area ?

Sometimes I would go down to my memory lane to look at my old stomping ground.  There is day-burning MV blaster still going on at https://maps.app.goo.gl/keqG2cuRhUsj2o6C9

Yes, I do this too. I’m almost always on the lookout for HID fixtures, and know where most of the nice ones are, but it’s always fun to discover ones that I’ve overlooked, or explore areas I’ve never been to.

It’s a shame when a very old fixture gets unceremoniously replaced with another LED or removed altogether.

Still there are a good number of various types of HID fixtures on private buildings, yards of homes and in parking lots, even though all of the MV fixtures on public roads have been replaced now and the HPS fixtures still are dwindling.

The ballast in arm fixtures like the GE and AEL were my favorites as a kid, a few abandoned ones remain. My local power company only disconnects the fixture if the customer doesn’t want it any longer, so quite a few old out of use NEMA heads and bracket lights remain up but long unused.

I do this by default, on my way home from work, since many Mercury Vapor and HPS Cobras more recently got replaced by LE... sigh... LED.
As far as memory lane drives in areas I use to live in back in the day, around like 2007, I sometimes found myself taking the Genesis for
a drive around Beavercreek Ohio, for this very reason... remembering the HPS or MV Cobras that use to be in those neighborhoods.
I've got absolutely no interest in the LED street lights that are there now -- there's just nothing remotely interesting about any of them.
However, there are a few old school fixtures still lighting the streets in Beavercreek, like on Indian Ripple road. Plenty of tear drop HPS
street lights still illuminating Indian Ripple road, and it's been that way since back around 2011, so... 2011 or 2010ish vintage with those.
Unfortunately a couple of them have been removed completely and I don't know why.