Over-thinking in golf is caused by similar feelings as over-thinking in anything else in life. Fear is what lies at the roots of over-thinking.
Fears come in many shapes and forms and plague a golfers mind unless you know how to switch off and change your focus. Fear that you haven't made the right discount golf clubs choice, fear that you haven't calculated the wind speed correctly, and fear caused by not being comfortable with that particular shot or club, fear that your playing partner is catching up with you, and fear that you're just not at one with your swing at the moment. Every golfer has experienced these fears and many more too.
Fear is debilitating. Fear freezes you and inhibits your swing. Your mind and your swing go all over the place as a result of fear. Fear that you might hit a bad shot with the discount golf clubs makes that result an almost dead certainty.
In golf confidence is King. When you are confident in your stroke, confident in your swing, confident in your shot choice and so on you find that your body responds freely and masterfully to this mental state. Golf confidence is what stops those fears creeping in. Golf confidence stops those myriad thoughts from whizzing around your mind and strangling your ability to focus and swing with your discount golf clubs freely.
You hear golfers say that they need to get out of their head and just play the game. What they really mean is that they need to shift a gear in their mind, move into cruise control, with clear focus, trust and confidence in their swing.
How does someone like Tiger, hailed and acknowledged as the most focused and confident golfer ever known, lose this golf confidence, trust and focus? It's a long time now since he's won a major, and he was the guy we all thought would top all known records. What caused that loss of faith in him?
Surely though, despite his working on mechanics, he of all people has a strong enough mind to overcome those fears and niggling doubts? I cannot help but think that Tiger has overlooked the importance of his mind, underestimated the power of a golfers mind, especially his mind. He used to have a real balance between his mechanical focus and his mental focus. Now it seems that all of his attention is being placed upon the mechanics of his game, and this is messing with his mind.