You can achieve almost anything you want in life if you focus your energy in one thing.

From the moment that you wake up if you are fully rested, you start to use your energy. If you have multiple things to do then you are spreading the energy amount all the things that you have to do.

Eventually, depleting most of your energy which in turn will force you to rest because you will be too tired to do anything else.

Instead, you ought to focus all your energy in one thing. Once that thing is completed then you can move to something else.