I'm a bit of a mixed bag when it comes to this. I know my height and weight in Imperial, and have to convert if necessary, which I can't do in my head.
I know that a kitchen cabinet is 60cm wide (and although I do know to divide by 30 to convert back to feet and inches, I don't do that when it comes to white goods.
Sugar comes in 2lb bags and butter in half pound packs in my head, but petrol in litres, and wine in 70cl bottles.
I definitely think in pennies and pounds, not lsd, but I could convert - I was quite good at adding up pretend shopping lists and working out the change from a ten bob note when I at schools nd could probably do it again ??.
I could go on, but you get the idea. It's nothing to do with being well educated or otherwise, IMO - it's about when you learned to do the relevant things. I didn't need to know about wine quantities or kitchen cabinets until long after decimalisation, but I knew my height from when I was 3' 4" ?.
Oh, and my babies came in inches and pounds, and they were born in 1991 and 1993.
If the idea were to revert to an Imperial standard (which I don't think is happening) I think it would be daft, though. Generations of people have learnt to do things in metric, and there is no point in undoing all of that. Plus, we import more than we did when I was a child, and more things come pre-packed (when we can get them) and printed with metric weights. It would add yet another layer of bureaucracy to trade.