Crossword puzzle clue "one who's in it for himself"

"___ should keep himself to himself": "Treasure Island"

"Man will do many things to get himself loved, he will do all things to get himself ___": Mark Twain

One who's often not himself?

Words from one about to quote himself

One who talks only about himself, say

One who always finds himself over a barrel?

One always in search of himself

One forcing himself on others