r/Mammillaria

The reason why I am asking is because last summer, when I had multiple mammillarias blooming, I tried to cross pollinate them and I didn’t see any fruits really just a couple so I thought I had failed. Well fast forward to a month ago, I have all my plants inside under a strong LED grow light in my mammillaria started to not only bloom but push out fruits!!!! and same with another one that I have! I was completely shocked. Does it just take a very long time for the fruits to form??? does anybody know why this would happens once they are indoors and I wasn’t even trying to pollinate them?? I found it to be such a strange thing, so I thought I’d ask if anybody knows any information on this? Also, I have seen people remove the pods before they dry, and why do people do that instead of waiting for them to dry and then pull the seeds off?? thanks in advance!

Mammillaria bocasana flowered first time