In the world of philosophy, there is a huge debate between determinism and free will. The former says that our actions are determined by our past while the latter says that our actions can be chosen freely.
I have nowhere near the amount of knowledge and wisdom to say which one is right. What I will say is that it would behoove us to act as if we did have full free will, even if it isn't true.
That's because belief in determinism usually leads to inaction. Even though they may not know it, some people invoke determinism as an excuse to not improve their lives. You can see this with how they deflect personal responsibility: They may say "I was just raised this way" or "I couldn't get it done because of this other person."
That may be true - and it may actually be important to be aware of those causes - but what is more important is what you're going to do about it.
Another problem with people that believe in determinism is that they fundamentally don't believe they can choose to change. Instead they wait for "the universe" to tell them when it's time for a change. They usually wait until they get a big health scare to start exercising or they wait until they get into a car crash to start driving more responsibly. Sometimes it may be too late.
Imagine how much better it would be if those people knew they could change their bad habit before a defining moment?
What we need to do, if we want to improve our lives, is to act as if we have full and unfettered free will.