b/c when you say "I didn't see anyone being selfish or doing it for themselves" it still infers a negative connotation on the word selfish, as if the mourners would be doing something bad.

Instead, think of it as "the entire grieving process is an *internalized* ordeal. all of the things that you feel, and all of the emotions that you show, and all of the people you talk to about the way that you're feeling are steps in a process that allow YOU to feel better about the pain that YOU feel, and come to terms with the loss that YOU experienced. The process ends when YOU are able to move on with your life after the loss YOU experienced, and can cope with the pain YOU feel inside."