There's a potential problem that gets touched on sometimes in philosophy, but rarely explored. Most people believe that it's morally good to make sacrifices for others. But what if two people both take that to an extreme? Say they are starving and both have a small piece of bread. They would both try to get the other to eat both, and as a result would not be willing to eat either piece themself. The result is catastrophe: they both die because they were too kind. But is that really how kindness works at high levels?
I present the following claim: you should not try to put others above yourself, only equalize them. That is, if you have two pieces of bread and they have none, you should (assuming you're both equally hungry) give them one but eat the other yourself. This way, there is no conflict. No catastrophic result if two people are both extremely kind.
This also means if you are ever the beggar that someone is trying to donate to, you should accept the money, even if you are a saint. But that's not the selfless thing to do! Come on, give other people the chance to be kind too.