I can't say I'm retired, as I can't draw Social Security for 6 more years, but I've always been a stay at home wife. I guess that qualifies as just plain tired!
DH had to retire early due to health issues so he's on the couch watching TV all day. I wish he was able to be up and about but he can't. Him being in the house all day long just wears me out and I can not get anything done. It's a mental thing.