Most of us are consumed with our own thoughts and desires and are not always thinking about what other people may want. This is not necessarily being egocentric; it is just being human.
Not being in tune with your customers is like living in an alternate reality; the way you think your customers feel about your product is not always the same as what your customers really think about your product.
One's work usually occupies more than half of one's waking life. Choosing work that does not bring happiness will lead to a life that is mostly disappointing.
The concept of the "good ol' days" must be one of our society's biggest delusions, top reasons for depression, as well as most often used excuse for lack of success.
Show interest in all people, not just those from whom you want something. Making people feel important and good about themselves is just the right thing to do.