One of the nice things about marrying someone from a very different background yet with many shared interests is that life together can be really fun. That particular conversation (what are the most important inventions) probably spanned more than a decade. It was not the only such. Sometimes a topic would go into abeyance and then one of us would read something that would reignite the topic for a while.

I don't think either of us would have ranked the JSC #1, but in the top 5 or so, sure. It's not like one can definitively generate a proper ranking, but some things are clearly top 25 but not top 10, for example.