I think the translation "I wish for everything" is wrong. The german translation for that would be "Ich wünsche alles". The correct translation should be "I wish everything for me". The sentence "I wish for everything" does not necessary imply that one wishes for himself. In order to be exact, I would say, I wish everything for me.
What does "selbst" express and add to the sentence, that "mir" does not?
Eg. in English, "I bought me a car" and "I bought a car for myself" are effectively synonymous, even if the use of "myself" is considered the proper construction these days.
Here, the phrase literally goes "I wish to/for me all/everything".
I guess I am curious about what exactly triggers "selbst" and what does it contribute to the sentence.
Mir/Mich and Dir/Dich are the reflexive pronouns for the first and second singular person. Uns/Uns and Euch/Euch is for the plural ones. Sich is used for others