When we were doing our time for our Habitat for Humanity house, my ex-wife and I framed houses on two different days. Within an hour, my arm was numb and I couldn't hit shit.

I just redid my bathroom. I could go 30 mins tops swinging a 3 pound hammer before I was done for the day.

Well put. Thanks for entertaining my pedantry.

Generally, most of the tools in the house are considered "mine", and yes I do often break out in a dry sweat when my wife wants to borrow them.

This isn't because I don't think she could learn to use them, but rather because the only time she picks them up is when she's in "get it done" mode in which case a fuck up is costly in terms of time and money to fix... we me usually being the one to fix it. I'm pretty sure she similarly shudders when I grab a needle and thread from her office. We have a truce on laundry and dishes.

Thing is, I've got a shop full of bits and pieces where I fucked something up. BUT, I generally fucked it up on the inexpensive test projects until I was happy I could do a reasonable job, or where the cost of failure was just generally not too high. I don't believe that my wife couldn't similarly become a good carpenter or whatever, but rather experience says that she doesn't have the interest of patience in learning to do so.

The trick for hand saws is sharp blades and patience. Don't rush it. If you put it where you want it and have patience, most things practically cut themselves (save for something like a tree). If your blade is dull, you're more likely to make a mistake.

Why was your BIL required to use a hammer after marrying your sister. Is there some ritual I am unaware of?