Disprove that Humans are selfish Psychological egoism, can anyone provide an everyday action which a healthy human mind would carry out which doesn't have the motive of preservation of the individuals own life at heart?

For example, some may provide the example of forming friendships or falling in love. However this is ultimately because forming relationships with these people is mutually benefit since they will both have someone to rely on, crucial to Humans, who are social creatures which would struggle to survive by themselves.

Interested to see if anyone can dissuade me from this dark outlook of Humanity.
Giving a dollar to homeless people on the street serves no aid to the donor, since the only difference is who has that dollar, and clearly to have the dollar is better than not.
This action is therefore entirely altruistic.