Determinism doesn't really say that tho, it just says that events are predetermined, not that you must accept that or that doing so is the meaning of life. You can just as well be predetermined to not accept it
That's exactly it. Determinism is the idea that all the various forces of the universe impact things in such a way that, however things play out, it's how they were always going to.
Imagine a time in your life when you made an impactful decision, and imagine you can go back in time to that moment. However, when you do everything is the same - you're thinking the same thoughts, feeling the same feelings. You've had all the same experiences, and are in the same frame of mind. Every single atom in the entire universe is exactly the same as it was in that moment. Would you ever actually make a different decision from what you had in that moment?
Determinism says no - if you had the capability to know the exact state of the universe in a single moment, you'd be able to tell what the next moment's state would be, and on and on to the end of the universe, since it's all nothing more than a single incredibly complicated chain reaction.