Interesting first day back lifting heavy

Ill be the first to admit i havent lifted as much as i should have.

so, today i went back to the gym, a lot lighter, and tested myself.

What i realised is it seems my body doesnt eat muscle evenly! My leg curls were higher than before, up to 210lbs now, arms pretty much the same, back similar, the my leg press was down 20lbs! from 400lbs to 380lbs! Seems my body didnt want my glutes!

Is this normal?

On the flip side i used to row 1000m in 5 mins, really pushing it from the start, and at the end hardly able to breath. This time i only thought about it halfway through, blowing a bit by the end, but did 1161 in 5 mins! Although, at the the end my forearms where in agony! Not a "leg burn doing cycling" agony, but a real vice like pain. Went after away about 30 seconds mind. Is this normal?