Some people may say that it is a bias to the things you like. Yes, it is and sometimes it is dominant to such a degree that we forget about good or bad.
Thoughts exchanged is knowledge gained.
It usually starts off as a simple issue of a grandchild throwing things, the student not completing assignments or the employee coming late. This gradually grows to an extent that mistakes become more common and does not attract penalisation.After some time we have a child who has temper tantrums, a student who becomes lazy and an employee who become unproductive and has a negative influence on other workers.
We have to like someone but be fair and strict for their own good.