> I feel ashamed that my selfish life feels pale in comparison.

You’re still alive, thus you still have the chance to live a more selfless life you feel proud of.

> It's amazing these people did not worry about the extra expense and inconvenience of taking care of another person

Seems to me they did worry, but decided to do it anyway.

> with children of their own to take care of.

The children came later, and Ronnie helped to take care of them.