Persistence is the iron quality of success; if you persist long enough you must eventually succeed
The greatest enemies of success and happiness are negative emotions of all kinds.
Never criticize, condemn or complain in a conversation with a customer or prospect.
The more reasons you have for achieving your goal, the more determined you will become.
For every difficulty that supposedly stops a person from succeeding there are thousands who have had it a lot worse and have succeeded anyway. So can you.
Accept complete responsibility both for understanding and for being understood.