Settle down brother, we're all friends here. :eusa_eh:
I use my legs a lot and they don't get tired. I use my arms a little and they do. That says to me my legs are in better shape than my arms, which is a reasonable assumption seeing how my arms are twigs.
I'm not opening the guard like a douchebag, I'm using a methodical guard pass taught to me when someone is giving me a lot of difficulty with a closed guard, which is most always. I make some distance with my hands at their arm pits, then use my arms to work my way down their chest till I can get a good position locked in on their hips.
I'm not looking for an easy fix, or a crutch for bad technique. I have 2 days a week available for Jiu-Jitsu, so I try to make the best of my time. If my arms give out, I can't work on that part of my game. If I can toughen up my arms a bit, I can work more on my technique.