By your intellect you know that you need to add a new good habit to your life. Through your intellect you know you have a bad habit you need to get rid of, but knowing is not enough to change. In order to change, you need intellect, the knowing, and courage, the act of the will, to make meaningful and constructive change.
The "act of the will" is the single most important concept that will change you. You will break bad habits with an act of the will, you will add new habits by an act of the will. However, the most important ally and the most stubborn enemy you have, is the person that looks back at you from the mirror.
The act of will that can change you is only stopped by you. You might say, "I don't know enough about...." Who cares, jump in, get started, you will learn. You might say, "I don't have enough time to start doing..., " that's just an excuse. You know that if you start a new program of change in your life, you will see other less important things drop away, like the distracting habits of TV, video games, and social media. You will make time by an act of the will, and you will break bad habits and/or make new habits by an act of the will.
You will change plenty of things and make much more time in your life when sudden, severe events occur, so why not voluntarily make your own sudden event and make a change. Don't let external events determine how and when you will make personal changes for the better. Take charge of yourself and make the changes you desire now, on your own terms.
Intellect (knowing that you should change) and courage (taking the action to change) are both necessary for someone to actually change.
An act of the will can make all the difference and change every one of your tomorrows. You have the courage and intellect within you, don't let fear, excuses, and self-doubt keep you from taking action, making that first step, calling that phone number, enrolling in that class.
Will it be hard? Maybe, but some of the hardest things make us so much better. Will it take time? Yes, but that time is going to be used up and pass you by no matter if you make a positive change or not, so why not use whatever time it takes to make the change you want?
Right now, your intellect is telling you that you know you should make that change you have been thinking about - knowing is not enough - make an act of will happen and make that change. It will be worth it.