One-sided love.

 I thought one-sided love only occurred with lovebirds, but now I see it happens pretty much everywhere. 

Parents give their favouritism to one child, but the other loves them more; they do everything for them, but parents always prioritize their favourite child.

In the office, someone works sincerely and efficiently. The management likes that, but the management likes another person who can gossip with them, drink with them, be talkative, etc. That favourite person doesn't like management or the company; they just behave like that to achieve rewards from the management, and they succeed. Nobody cares, actually who is making their company bright.

In friendships and in a group, sometimes you will see that you like someone and do whatever you can, but that person still likes to enjoy time with others. 

It's the choice of hearts. No one can complain about it. It doesn't work logically.