Many people wear pyjamas when they're not going out, just for comfort, and it doesn't necessarily mean that they've slept in those same pyjamas. Someone once expressed amazement that I'd wear my jeans in the house, and it took a good while for me to get my head around what they meant. For a long time I never wore pyjamas for bed – just me and the duvet, but in recent years, when I've got dressed and if I'm not going anywhere, then it'll be pyjamas, particularly in winter when I want to save on heating; when
I'll wear ones like these. It also helps if they have pockets. Not pointless. But then we're not talking about your silk pyjamas, Alan.
Approximately one-third of men in the UK wear pyjamas at home. Such deviance! Nowhere near as deviant as going shopping in them, though.