re: i don't understand how wanting/not wanting to stay locked down

Flattening the curve is still operative though, as "raise the line" is too (increasing system capacity). If more people move around, R0 goes back up and case growth grows in exponential fashion until we've got herd immunity. If we can keep R0 down through smart testing & isolating and get more effective treatments then we can feel more comfortable that more social contact will work out ok.