You're Correct!

It is nearly impossible for a golf ball to fly in an absolutely straight line. If nothing else this is due to environmental factors such as wind and the slope that the golfer hits the golf ball from.

Both factors are nearly always apparent during any golf shot and both will make the golf ball curve to some extent in the air.

Aside from the environmental factors affecting the shape of the shot, there is also nearly always a natural shape to a golfers swing that produces a specific curve on the ball. Examples include the following:

Ernie Els - Draw (right to left)
Jack Nicklaus - Fade (left to right)
Lee Trevino - Fade (left to right)
Bubba Watson (left handed) - Fade (right to left)
Lee Westwood - Fade (Left to right)
Jim Furyk - Draw (right to Left)
Rory McIlroy - Draw (right to left)

All of these players swing in such a way that, unmodified, the shape of the shot moves slightly from one side to the other in the air. It is important to play with what is natural to you and not fight it on the golf course. That is not to say that you dont need to change the shape of your swing. It may be preferable for consistency and distance that you make swing changes to create a new natural shape of ball flight. Tiger Woods and Nick Faldo have both done this. The key point is that you must play with what you have on the course and change what you have on the range - do not mix the two.

The final point regarding straight shots is that it may be preferable to move the golf ball in the air from one side to the other - to hit into a green, down a fairway or avoid trouble. This is when a player fades (left to right for right handed players) or draws (right to left for right handed players) the ball. Moving the ball in a certain direction can sometimes be preferable to hitting straight.

Examples are:
- When the ball is behind an obstruction - curving the ball around a tree.
- When there is trouble down one side of the hole - curve the ball away from trouble.
- When the hole doglegs around a corner - curving the ball to follow the shape of the hole.
- When the flag is behind a bunker on one side of the green - curving the ball around the bunker and into the flag.

Curving the ball is an advanced skill but one that can be well worth learning how to do.

We spend a lot of the time trying to hit the ball straight but sometimes, curving the ball, or playing to your natural swing shape can be more fruitful.

True, but sometimes there is something in between those two points that does not allow you to hit the ball straight. Also it can sometimes be more beneficial to curve the ball, such as around the dogleg corner of a hole.

Unfortunately, there is no such thing as perfect in golf. Perfect suits the conditions of each shot and each shot is different and demands different characteristics. These are not always the characteristic of hitting the ball in a straight line.

What if the golf hole is a dog-leg? Hit the golf ball straight and it ends in the trees through the corner of the hole. The middle of the fairway is the outcome but what is the process of getting there?