Personal skill sets. The more skills you have command of, the less you need to stock because you can do more, with less.
Over the years, I've come to realize that financial stability is probably the number one thing to work on with regard to preparation. There is zero point in stocking up on, anything really, if you are still making credit card payments on, anything really. I think you're pretty squared away financially, but if I could go back 10 years and start all over again, that's where I change how I view prepping and survival.