From Huffington Post:
Marriages don’t just fall apart overnight. They often end after months and years of both spouses trying to stick it out, firm in the belief that they can work out their issues and sustain their marriages.
Once it’s over, though, most divorcés can look back and pinpoint one exact moment — one overblown argument or one instance where their spouse showed his or her true colors — that should have signaled to them that the marriage was damaged beyond repair.