So many things can make Mondays demoralizing when you dwell on negative thoughts.
The mind has become used to resting, so it takes ages to get back into the working mode, which makes people feel like they are useless/slow/unproductive.
As hard as it is to find out your partner has been cheating on you, I guess it's also hard to come to terms with who you are and your sexuality. Years later, they're both in happy, healthy relationships and are still on good terms. Makerbot2000 heartbreakingly shared, "Late to this thread, but what the hell. But then we had the year to end all years — lost 3 out of 4 parents (her Dad had died a long time ago) in a single year, moved to a new house that was still being renovated, and she went back to school to start a new career. He's a closet alcoholic, he hides the bottles in the bottom of the recycling bin. He was working 30 hours a week when he moved in then asked for reduced hours because he couldn't handle it, now he's at 15 hours and says he's looking for another job because he can't make ends meet.
The husband and wife agreed to split amicably and the rest of the family were all really supportive, including the kids. If you don't like any of the same things or have some similar interests, chances are you won't have things to talk about before long. Some really hard stuff happens and it just doesn't work anymore. Job changes, family dramas (sister tried to kill herself), and it was like we were a team that could take on what life handed out. After living with him for six months I've asked him to move out, and I can give him a reason for people not wanting to be around him. He was unemployed for 3 years while married yet never learned basic skills like cooking or cleaning.
It is interesting to see that breakups increased at certain points in the year than others.