Is it just old age ....

I also upped drinking water (I was probably slightly dehydrated) and started talking a multivitamin tablet daily (I wasn't eating particularly well) so that possibly helped too?

Yes LL that's the answer ! I have to consciously tell myself what I've just done. Put the keys on the mantelpiece, parked the car beside the trolley hut thing, letter to post on the stairs. And so on. I always now check the hob knobs (gas top not biscuits !) before bed, and check I have actually turned lights out. I've done some of the things you list but not all on the same day. I think this time of year adds to our forgetfulness too but I feel reassured by friends all saying much the same. I recently left the keys in the front door overnight, and have more than once tried to open it remotely with the car key. Never mind. It might be more worrying if these things didn't bother us ?

I've noticed it too, more especially since I retired, although I was only working part time.

I think the lack of a structured daily routine and sometimes less contact with other people can have a detrimental effect on our ability to focus on 'the here and now' which can lead to slight confusion and perceived memory loss.

Establishing a new routine would probably work for me, but I agree that stress can be a big factor.

I'm 62 too, and had a spell of thinking I was seriously losing it last year. Luckily it resolved itself by my consciously thinking about what I was doing (I'm guilty of not concentrating on what I'm doing!) and deliberately slowing down.
It wasn't easy after many years of working ridiculous hours and being unable to sit and do nothing but it seems to have worked!
It is definitely stress related.

I think having a lot on your mind has a lot to do with it, based on my own experience!

My memory has never been great either, but it does get worse with age, sigh.I almost burned out a pan last week , forgot it was on.So, it's not just you tizliz