[quote=So Boerd]
Thinking about it is effectively beyond your control. Doing is not, and doing makes you selfish.
[/quote]

This is rare but I agree with Turt.

What's selfish is forcing people to stay alive who don't want to live just because you don't want to see them go.
For an example some people may relate to more.

Let's say you're in a relationship and your partner wants to end it but you don't.
So you basically go "But I don't want you to go! I'll be sad/hurt without you!". Is this behaviour/reaction understandable? Yes, you care for the person and don't wish to let them go. But by pressuring them to be somewhere they don't want to is what is being selfish.