This is a bit of a weird one.
When I was a kid, say 6/7/8, I'd always scamper up steepish flights of stairs on all fours.
Now I'm in my fifties I've suddenly started doing it again on my home stairs (not in public, although that's a hilarious image). Stairs are steepish, but no steeper than they've been for the last ten years I've been living here, and have got newish nice soft carpet. It suddenly seems like the natural thing to do if my hands are empty.
Does anyone else do this? Should I contact the HRT manufacturers to report a strange side-effect? Is it the sign of a hitherto unsuspected neurological condition?