As a big GSP fan I hope he retires. Mentally he seems to be all of the place in recent fights.
What has he left to prove?
Not true that's just an easy excuse for people who are fans of GSP to say he's better than he actually is. The reality is his last 3 opponents have hit him more than the rest of his combined opponents because they are way better than everyone else GSP fought in the rest of his fights.