There is not a single typo displayed on this image.
shouldn't 24 going on 35 be 34/35 or 24/25? or do i just not understand what that phrase means
No. It's a joke. he's 24 but feeling like 35 because his back is hurting from sitting on the floor for 8 or so hours.
It's a lot less impactful when I have to explain it haha