钱学森 as a human being, he MUST love himself first,
then, started to think about doing anything BIG/GOOD.

Like HunHun mentioned before,
FUN and RISK
needs to be balanced.

He did a lot for USA and he got a lot from USA,
he risked himself a little,
USA disciplined him a little,
He did a lot for China and he got a lot from China,
he had FUN in China,
he risked himself a little in China