I have popped seeds 7-8 years old and I have had fails from seeds I just bought. You never know how old they are when you get them. I think its called "nicking" when you take a set of fingernail clippers and cut off the pointed end, the times I tried it was called "find the seed before the cat does". I have had good luck lining a match box with sand paper and shaking the seeds in that for a while to thin the shell, but for all I know they would have popped by just dropping them in the media or water + H202