The last one always takes forever to crack

Fun fact: I once used a glass to crack open the “middle finger” cause I had nothing else hard enough close at hand.
I felt like a true monke

I once used a rock to crack a mostly-closed one, and it dented my IKEA desk.
I have a pistachio shaped hole there now, it's hella annoying.

I almost always end up with the "middle finger" ones since I'm the only one willing to fight them. I open them by placing them, seam vertical (still lying down), on my back teeth and slowly applying pressure. If it's especially tough, I just let it sit there for a bit and let my saliva soften it up a bit before trying again.