Me, earlier: I'll go to bed early, then I'll feel much better tomorrow morning. 😌
Me, at 1am: squinting at moment of inertia/deflection calculations ... no, that's definitely coming out wrong, and I am clearly too tired to see why. I have screwed up two things tonight!
(I assure you, if I put 5 tonnes' worth of pull on the middle of a 50x50mm 3mm wall box section that's otherwise fixed at both ends, I will be bending it a damn sight more than 33.8 femtometers.)