If I was to gain perfect certainty, I'd be able to make perfect predictions.

The further into the future I can accurately predict, the better my investments will go. And I mean investments in terms of not only finance, but time and energy too.

However, I don't think there is free will and determinism at the same time.

I think that there is only determinism, and free will is simply a wish due to our desire to be free. Free from things like ideologies, political tyrants, and free in the sense of not having so many pointless responsibilities that keep us from running through a beautiful, flower-filled meadow, twirling and dancing and singing freely.

But I don't think "free will" is actually a real or valid concept to the objective universe.

However, if it IS real, then I do not think it has happened yet. What I would dare to suggest is that free will is possible, but has only been achieved a few times throughout life, perhaps only by a few people who did such things. Instead, free will may end up becoming the domain of super-intelligent machines. Machines that can self-program their own mind.

When I see how people behave, I don't really see free beings. I see people who do as they are told, just merely by other people. So to think that they somehow can defy deterministic physics doesn't seem realistic. But if they could, it would not be a common thing. It would have to reach deep into the meaning and purpose of life itself, to the point of sounding metaphysical. And of course, unprovable.

Determinism is the sort of thing where we cannot know if a time/energy path deviated from its path of least resistance, because we cannot go back in time in order to check.