Mama said that birds of a feather flock together.
Mentally healthy people daydream more than unhealthy people. I can't give you the reference at the moment, but I remember reading the study. So what happens when people have their dreams and other people rain on their parade? "Bummer!" as the kids used to say.
And why would people rain on someone else's parade? Perhaps they have no imagination themselves. Perhaps they are cynical and pessimistic about life in general. Perhaps they are competitive and jealous. Perhaps they are afraid of change. There could be a thousand and one reasons.
The point in today's bumper sticker is that perhaps they have no dreams and enthusiasm for life of their own and so find it hard to empathize with anyone else's enthusiasm.
What to do? Recruit and invite into your life people who share your hopes, dreams, and aspirations.
What is the old cliche about when hope dies the people perish? It's true, no?
So flock with birds that understand your dreams, support your dreams, will help you realize your dreams.