Too often we spend too much time talking about doing things and not enough time doing them.
When it comes to quitting smoking or losing weight, there are definite ways to do it, they are so simple it seems ridiculous to even think of them as a way to do something. If you want to lose weight, do more exercise, if you want to give up smoking, stop buying cigarettes, if you want to write a diary, sit down and write, every day.
Why then do people find it so hard to do these things? Is it lack of will? is it lack of drive or motivation? Is it laziness? Probably. Overcome these and you will succeed, it's easy!
If you want to be the person that does things, whether it's quitting smoking or changing the world, just get on with it already! What are you waiting for?