Many will try to give of themselves when they do not have enough of a self to give. This often leads to feelings of resentment and bitterness. Often people give with strings attached, hoping to get in return.
Jesus sacrifice was so huge because he had a full self to give away. One’s “yes” means nothing if they are unable to say “no”. Similarly if one does not do the hard work to define their “self”, they will be offering parts of themselves they do not fully “own”.