pollyanna again

I do understand that nothing has changed except the thinking….
What I wanted clarification on is when we brainstorm all of the things we want from people in our relationships and we know that they do NOT do any of these things, how are believing these thoughts helpful when they are not based on reality?
Does this make sense? If I wish my MIL communicated better, planned more and wasn’t silent during her visits- I would have certain thoughts like, she’s so pleasant or I really enjoy her company! She doesn’t do those things, so how do you get yourself to go to these “unbelievable” thoughts?