One moment we said to a person, "You are very nice."
Another moment we said to the same person, "You are not nice."
It is not about that person is being nice or not nice.
It is our own mind keeps changing from good mood to bad mood, and vice versa.
When our mind is in good mood, everything we see and hear is nice, good, and fine...
When our mind is in bad mood, everything we see or hear is not nice, irritating, and frustrating...
Whatever the mind perceives is a reflection of the mind itself. The mind is the projector of all the names and forms.
If the mind is full of errors or defilements, then whatever it knows is contaminated by these errors and defilements.
Purify the mind, remove all errors and defilements, all the names and forms are just what they are. They are neither positive nor negative, neither good nor bad, neither happiness or suffering.