Parental investment is the key to understanding sex differences in mating strategies.

I'm sick of it as well. But I'm sick of not doing anything about it.

You are always a valuable, worthwhile human being — not because anybody says so, not because you're successful, not because you make a lot of money — but because you decide to believe it and for no other reason.

解读：不劳而获、投机取巧所得快乐转瞬即逝，唯有持续付出汗水与心血，攻克难题、实现目标，由此产生的快乐才扎实、长久，激励踏实奋斗。