When you love someone completely you want to be their last love because they will be yours. You will no longer want to be with anyone else because you no longer see anyone else in that way, only the most beautiful and special person in your life you love.
Sometimes this quote represents a healthy commitment to keeping dangerous people from creating drama in our lives, sometimes it's just a bullshit excuse to push away those we know would hold us to the fire. Know which aim you're taking before making thus kind of decision. Self-respect is one thing: no one should be a doormat. Loving through striving is a whole different ball game.