I think I lost track of what we're talking about... Rigor is the crux of what? (To clarify, the reason I was comparing research to starting a startup was to s

I think I lost track of what we're talking about... Rigor is the crux of what? (To clarify, the reason I was comparing research to starting a startup was to show how, even though a field appears to be immensely popular and having a lot of money and talent being poured into it, it is still possible for a determined person to make a breakthrough in it.)