Feelings

All feelings are valid.

Therefore they should be acknowledged, end of story.

Instead we think about them and assign a value to them, rendering them valid or invalid.

We choose between a thought and a feeling. If they match:

 I feel happy + my thoughts are 'that's a good feeling' = no conflict

I feel sad + my thoughts are 'you shouldn't feel that way, that's not good = conflict.

I feel sad + that's okay = no conflict.

Best of all:

I feel sad. 

No excuses, apologies or explanation needed.