Illness or injury can also be a factor. A sick or injured Meowth might not be able to do the things it normally does. It could be left behind by its group or not be able to fend for itself, which would be a really sad situation.
Another reason could be unrequited love. As I mentioned before, if Meowth has feelings for another but is rejected, that's very painful. It can lead to a long - lasting sadness.
One sad Meowth story could be that Meowth was in love with a female Meowth. But she rejected him because he could speak human language which made him different. He was left all alone, feeling heartbroken and out of place in his own kind's community.
One possible reason could be the loss of a loved one, like in the case where the cat's owner died. Another might be separation from friends or family, as the cat that lost its mouse friend. Or neglect, such as when the family focused on the new baby instead of the cat.
One reason could be neglect. If the owner doesn't take proper care, like not feeding it enough or not providing shelter, the horse would be sad.
One reason could be the difference in their destinies. Silver is often tied to the future of his own world, while Blaze has her own duties in her dimension. This can lead to a sense of separation and sadness. For example, if Silver has to go back to his time to fix things and Blaze can't leave her world, it's a sad situation.
One possible reason is the pressure of always having to be perfect. As a virtual idol, Miku is expected to look and perform flawlessly all the time. Any glitch or mistake could be seen as a failure, which might make her sad.
It could be that Alan was betrayed by someone he trusted deeply. A friend or a business partner might have let him down, and this betrayal would make him feel sad and lonely, as it shatters the trust he had in people.
Illness could also be a factor. Just like in real life, if the dog in The Sims gets sick and there's no proper treatment or care, it can lead to a sad story. The dog would be weak and suffering, and its quality of life would deteriorate.
One reason could be poor management. If the management in a hotel or restaurant is disorganized, things like overbooking or slow service can happen. Another reason is lack of proper training for the staff. For example, if waiters are not trained well, they may not know how to handle customers properly.
One reason could be abandonment. Maybe its owner didn't want it anymore and left it in the junkyard. Another is lack of proper care. In the junkyard, there's no one to give it regular meals or medical attention. Also, the environment is harsh. The dog has to deal with all kinds of dangerous and dirty things.
One reason could be misunderstandings. For example, the boy might misunderstand the girl's intentions and say something hurtful, leading to a rift between them.