Other people don't like to play with opponents who are having a bad day and find that this destroys their rhythm; if this is the case you have to learn to step back and not become emotionally involved or you will not be able to win. We each have our own unique temperament and emotional style; it's up to you to work out what works for you.
With an increase in the popularity of golf among the middle class and even among children, there has come a mass of media products to help you with everything from golf tips on grip to how to impress your friends with a terrific swing. With the internet putting the world at your finger tips it is easy to see how all of these things have grown in popularity. Who wouldn't like the idea of getting vast amounts of information right in your home to learn from and then going to the club and impressing your fellow golfers with what you learned?
I will say there are some other things that can affect you confidence on the day. Weather conditions, playing on a course you are not that familiar with, new clubs, an injury, and the ball you are using are some that come to mind.
In the golf swing you use virtually every muscle and joint in the body rotating around the spine. The upper body rotates in opposition to the lower body. By rotating around a straight spine you reduce resistance, can stay on plane in your backswing and through your downswing to impact and follow through. Limiting the variables and number of moving parts increases your chances of creating consistency in your golf swing.
Your golf posture is at the heart of your golf swing. A straight spine allows the greatest rotation with the least resistance. The moment there is resistance your chances of injury escalate for shoulder, golfers elbow, wrist, hip, back injury. Nearly half of all golfers have one of these injuries at any one time.
Club Head Speed - The speed of a swing determines the amount of power transferred from the club head to the ball. It also determines how far the ball will travel when it is hit on the club face sweet spot. But, speed is not dependent solely on a player's muscle power. Flexibility and body motion range are important factors contributing to a fluid swing that is powerful producing optimum club head speed.