Back in the days when they used to stack peanut hay rather than just let it lie on the ground like they do today, I was able to acquire a lot of peanuts.
The peanut picker came into the field and it just sat still and they brought the hay stacks to the picker which also bailed the hay as peanut hay is highly desirable, at least I think it is.
After a week or two, I roamed around the now cleared field and discovered there were lots of peanuts still in the field if anyone wanted to go pick them up one at a time.
Lying out in the Florida Sun for a few weeks had just barely cooked them. Not nearly parched but actually just about how I liked them best. I picked up enough to fill several paper bags full and ate on them for several years. They never did go bad which I think was a result of their having laid out in the burning hot sand for several weeks.
Sunflower seeds go rancid fairly quickly if exposed to air.
Peanuts last longer, but will still go rancid.