Religion. It's not science, and it's not at all accurate, but it's a process that creates knowledge. Experience. You can watch a thunderstorm and decide that Thor is throwing lightning bolts. (See "religion" above.) Again, faulty knowledge, but knowledge nonetheless. Imagination. You can dream about purple elephants. That's new knowledge. You can easily claim that all that knowledge is bad, useless, incorrect etc which is fine. It's still knowledge, and it's how humanity gained knowledge for millennia.