Actually changing a set pattern of behaviour can happen instantaneously. I saw this happen with my own Grandmother and it's a great example of what I'm talking about.
She'd been a smoker her entire life, and was the typical smoker who tried, failed and tried and failed. She also was so addicted that she hid her smoking from everyone and would convince them she'd stopped (she lied if truth be known...naughty Nan!). Point is, she L-O-V-E-D smoking. In her mind she was and would always be a smoker.
Then one day she went to her doctors, having experienced a few health problems, mainly with her eyes. It turned out that she had diabetes, and she was told that if she continued to smoke she may lose her eyesight.
She left that doctors surgery and never smoked again.
Something had shifted for her. The threat of losing her eyesight presented such a re-frame that the risk felt too high for her. And this is a good example of what happens when change is instant.
I'm sure you can think of examples from you own life or that of people you know where a similar thing has occurred.
Change can happen too by just deciding, but often fails and people quickly revert to an old pattern of behaviour, often as they end up just relying on willpower alone which is often a recipe for disaster.
This is why change that happens instantly, when paired with an external force like the health threat my Nan experienced, or some other kind of associated negative behaviour (to you, e.g. threat of redundancy, salary loss, a partner leaving), that change has a better chance of sticking. Think about disciplinig a child...effectively it's like conditioning your own inner child to do/not do something as there's a negative consequence.
This then also answers why, change takes time. It's not always the case that an external force is available to us, and as they're often negative associations, we don't readily seek them out.
There is another way though, and that is to tackle a change consciously and over a period of time. A good example of this is Slimming World or the like when you want to lose weight.
This kind of action based change strategy does a few things to help you make a change.
It allows you to set goals and see small incremental changes occur, where you usually can feel/see the benefit. It allows you to build a deeper understanding of what's going on and therefore what works for you what doesn't (which bodes well for when you dip or slip off your path), and it also very importantly this set up holds you accountable.
That accountability acts as that external force similar to what I mentioned before. It's also why people who want to change or improve in some way hire a coach or personal trainer, or even therapist of some kind to keep them on track. It means you're accountable to someone. Someone is waiting and interested in your results!
If you'd like to make a change and you're wondering where to start, I'd like to help you by sharing the work I do which I know gets results. It starts with you being open and delving into your thoughts and feelings about what you want to change.
In giving you something really practical, I'd like to then share the first part of the APE Model which is all set up to help you make a change.
These first 5 pillars are all about setting you up to give you the best chance of having a change stick. These 5 pillars are:
Vision
Goals & Definitions
Knowledge & Skills
Belief
People