The, "oh, you were too immature/neurotic/dumb to get married, it doesn't count, you get a do-over"* mindset would probably render virtually the entire human race incapable of contracting marriage.
I mean, I guess Albert Schweitzer and Mother Theresa could have been an item.
"Schweizteresa" wouldn't have quite the ring, gracing the cover of Us as "Brangelina," would it?
Benedict XVI recalled how "the Code of Canon Law's norm concerning mental incapacity, and the application thereof, was further enriched and integrated by the recent Instruction 'Dignitas connubii' of 25 January 2005. ... In order for this incapacity to be recognised, there must be a specific mental anomaly that seriously disturbs the use of reason at the time of the celebration of the marriage, ... or that puts the contracting party not only under a serious difficulty but even under the impossibility of sustaining the actions inherent in the obligations of marriage".
"We run the risk", the Pope went on, "of falling into a form of anthropological pessimism which, in the light of the cultural situation of the modern world, considers marriage as almost impossible. ... Reaffirming the inborn human capacity for marriage is, in fact, the starting point for helping couples discover the natural reality of marriage and the importance is has for salvation. What is actually at stake is the truth about marriage.
(*not the one employed by Himself's advocate, but still...)