DH not knowing obvious things he used to know

The thing that screwed me up the other day - ticks are arachnids, therefore 8 legs. But their larvae have only 6 legs. What’s all that about then?

OP whatever others are suggesting, a scientist forgetting these things by age 50 rather than 80yrs is certainly a concern.
They aren’t things you can forget.

I would expect anyone with an Oxbridge degree to have a large bank of general knowledge and to know that fish are cold blooded, that insects have six legs, that dolphins are mammals, that Antarctica is a continent and the Arctic is not, that Henry VIII had six wives, that Chrysler is an American company and similar without having to think twice.

If someone who had always had that knowledge seemed to be losing it, I'd suggest a check with the GP for B12 and any UTI.

Forgetting an old phone number, or the surname of someone you don't know terribly well, or the fine grained details of a specialist field you no longer work in is another matter.

Yes I'd find that worrying. It's the kind of thing I'd count as very common knowledge and I'm not remotely sciency. I'm really surprised by the number of people saying they wouldn't have known insects have 6 legs!

I can remember reading that an academic (I think it was Anthony Giddens) who said that they couldn't remember their earlier works or what they were thinking in any detail at the time. They read their earlier works as if they were written by someone else.

Functional memory is different. How to do something is stored differently from remembered knowledge about something.

If you are concerned you need to address this further.

The main reason I know insects have 6 legs is because of that film Arachnophobia that everyone was terrified of back in the day. I learnt spiders are arachnids because they have 8 legs. That's always stuck with me, probably because of how hyped the film was (think I was about 8 or 9).

Have you never forgotten something?

And the end of the day the brain is only a type of memory bank (think computer) you cant remember everything when the memory bank is full!

Nothing to worry about.

This thread has sent me down an internet wormhole and apparently fish are not all cold blooded at all. They are mostly ectotherms but a few species among sharks, tuna and others have apparently evolved some physiological temperature regulation.

It's a specious argument but maybe your husband is just up on recent research OP!

@Cheek2cheek I agree with what @VickyEadieofThigh has said. I didn't do science past (the equivalent of) GCSEs and my memory is shot to pieces. Utterly crap, but if even I didn't remember that fish were cold blooded I'd be very worried.

I'm 40 and have an Oxbridge degree. I have forgotten a lot of stuff that I used to know (and wouldn't be able to answer either of those questions). If I'm not interested or don't use the knowledge, it just gets replaced. It's only know that I have a 5 year old that give realised how much I've forgotten. On the other hand, I can still remember all the words to a lot of 90s pop songs.

I once read about a man who went to the doctor concerned because he could 'only' think 3 moves ahead in chess rather than 7 as per usual. He was laughed out of the office. Later he turned out to have Alzheimers and went downhill v quickly. At postmortem his brain was absolutely full of plaques, to the extent that drs were amazed he was functioning as well as he had. The theory was that he'd made such a conscious effort to use his brain, so he wasn't anywhere near as incapacitated as most people would be with that level of plaques.

My point is, degeneration shows up differently in different people and so if anything that's not normal for him is happening, you should get him checked out.

Millipedes are arthropods. Not relevant but interesting to know.
OP, yes it does sound a little worrying. Is he worried about it?

It's difficult to tell from a couple of examples. I'd be more worried about the insects than the fish but it's more the wider pattern. How is he functioning day to day with new (or newer) information?

I would trust your instincts and encourage him to see a GP if you are worried.

I would be concerned if happening frequently amd no other cause ( tired, stress , alcohol ect). Its more interesting because your examples are not so much memory but semantic / object knowledge. How worried is your husband and other concerns?

The first sign with my DM is she would tell me a story, then tell me it again the next day, then again the next week. Her long term memory was fine for ages, she still talked about subjects she had studied and old memories. But she kept loosing things.
And really started to bully my stepdad. I don’t recognise any of this in your DH’s behaviour.

Yes i agree this would be really worrying level of information to lose.
Perhaps you have some other examples?
I'd suggest keeping notes.

I think this is a potential concern, yes. The insect legs thing has got people confused. To OP's DH (as to me) this is a fundamental piece of knowledge, as basic as knowing that the sky is blue and there are 365 days in a year. Forgetting things is a part of growing older but forgetting something so very basic TO HIM could just be a sign of something. Get him to the doctor's, OP. No harm at all in ruling that something out.

Take him to the GP for blood tests, it could be something simple yet important like a B12 deficiency which is increasingly common with age.

Yes, I'd be concerned. That's general knowledge for most people. I wouldn't at all put it in the same category as labelling the parts of a heart at school, which is more specialised. It's more like forgetting that birds lay eggs or the BBC doesn't show ads.

I think you haven't given enough information for anyone to tell whether it's a concern or not - there must be more than this for you to be concerned?

If it's a relatively recent thing and does cover surprisingly basic (to him) things, he might have a UTI

This happened to someone I know, in his sixties, whose wife ask him to get watercress (which he liked) and he bought water and cress and was baffled when she asked why: next thing, he got super anxious, then was diagnosed with a UTI , all sorted out quickly with ABs

Hm... DH and I are 63yo scientists, I can't imagine either of us forgetting that insects have 6 legs or fish are cold blooded, it seems like the sort of primary school level general knowledge that gets embedded. But I guess we're both quite interested in nature, if I see a minibeast in the garden or out I may want to know what it is.

Maths is different... that's very much a 'use it or lose it' skill.

I agree with you op. I understand from these comments some people don’t know these things, but for us these are basics. I think there is something to be concerned about and I’d watch out.

Forgetting your address would be a big deal, forgetting "an" address is different

Personally I think it's a concern if it's things he'd normally know without thinking. I'd get him to have a word with his doctor as he's still fairly young.

It's a conversation I've been having with OH who'll forget everyday words while he's speaking. It seems funny at first but as it goes on I do get concerned. But he's a fair bit older than your dh.