Is it really possible to change old habits quickly and easily?
Yes, it is easy, and it's certainly possible to change any habit.
Consider this, suppose you change address but keep to the same place of work. You drive to and from work by car, and when you're coming home, even the first day you set out in a different direction to a different address. Now I know it's possible that inadvertently, one might just start off making the wrong turn or choose a road halfway home that leads to the old address. One might do this once. It is conceivable, one might do it twice, but not three times, surely?
How long did this changing habits take to establish? No time at all.
Now, you might think that this is a purely physical habit. Very obviously easy to change, and it is. But any habit, like this habit of driving can be changed in an instant. All habits are the result of thought. We think we are going home to the new address, and so we go to the new address. Let's consider another habit you might want to change. You are in the habit of answering back when your parent or partner asks you to do something. You only need to think "I am not going to answer back", and you do not answer back.
The only thing that is necessary to change a habit, however old, is to think of the new habit and your body will perform differently. You can always tell your body what to do.
Our whole lives are made up of habits, and these habits were mostly acquired in our younger days. We think that they are part of our very nature, they are not part of our nature, they are part of our nurture, part of the way other people wanted us to have or ways that we found helpful to us in living. Now if we have a habit that is not useful to us in living we can change it by changing our thoughts.
You might think all that sounds very easy, but habits are things we do without thinking. Yes, "without thinking", that's the problem. We do not think. We go around without thinking, as though we were robots.
Here is a valuable psychological trick we can use to ensure that we do not absent-mindedly jog along with our old harmful or useless habits: Imagine you are watching yourself, standing to one side, and simply observing whatever thoughts are in your mind. Do not bother about what those thoughts are, for the moment, but just observe them without emotion. Keep up this practice as long as possible, always if possible. This is called mindfulness and if regularly practiced will allow us to change our old knee-jerk reactions to situations. They will just fade away when the spotlight of attention is focused on them just as we change our route home when we sincerely change our thoughts about the journey.