Same age as me but the only reason I’m familiar with the word is because my wife has “sonambulated” since she was a little girl. She was a bad one too, even after we had been married for decades. She would routinely leave the house to pick tomato’s in our neighbor’s garden, toss the vacuum cleaner out the front door (convinced it was a bomb) and throw a fit because I had forgotten to make sure all the horses were in at night (we lived in the suburbs of New Jersey and neither of us has ever had a horse.) When our kids were older it was great entertainment for them, especially the night she claimed to be a pirate captain, did the “talk like a pirate” routine and kept in character for a good twenty minutes until I was able to get her back on her ship (our bed.)
sp. “somnambulated”