reply to u/drogers8 at https://www.reddit.com/r/antinet/comments/13wlfbs/how_to_select_a_keyword_for_your_main_card/
I'm don't think I've ever seen that advice anywhere in my own reading. I've been doing this for ages and would suggest that it's actively bad advice. Use a keyword that seems useful, beneficial, and which you're likely to have the most interest in in the future. What do you suspect the future you will use to search for that card or a branch on that idea in the future? Use that.
Also, don't overthink this stuff. Just practice. You're going to make some mistakes, but with a small number of cards you'll start to figure it out on your own before things get too large. Your practice today is not going to look like your practice in 6 months and it'll change again 6 months after that.