Thanks PJH, that was most likely it.
Mixelflick. Thanks for that info and obviously I was joking about morphine.
I wasn't 100% this morning as I was at the New Order gig which finished after midnight. A day of cardio intervals and 10+ miles of walking the strip and then a bit of dancing isn't ideal (no alcohol though - I refuse to drink the night before a barbell day!). Had a lie in but made it to the Wand MMA gym at about 8.30. A few stretches and squats with an empty bar to warm up and I breezed through the session and was only a couple of KG short of my squat PB so that will be bettered soon. The bad news? It felt too easy so I chucked in some deadlifts as I felt good enough and won't be lifting again until Monday. I've not hurt myself but its an old habit of mine in trying to do too much rather than trying to recover.
4/4/4 still in place and next week might try 3/3/3 or 4/3/3 or something. Just don't want to take too many everyday if I can avoid it otherwise a bottle won't last me long.