The laws of physics exist, therefore I am sitting on my bed with my dog and typing on a bluetooth keyboard while listening to Tool.
Okay, maybe I skipped a few trillion steps.
The fact that we live in a deterministic universe can seem to be rather disheartening. What am I without a will? Am I simply a robot subject to the whims of the creator known as physics? What's the point in living if none of this is ultimately up to me? These questions are to be expected as one realizes the true nature of things and their answers aren't necessarily obvious.
The fact that the molecules that make up this breath, and this breath, and this breath were destined to pass through my body at this exact moment from the beginning of the known universe is an absolutely beautiful notion. There is nothing I can do that hasn't been set in motion by unfathomable amounts of time and energy. There exists no action I could take that would surprise the universe, were it capable of sentience.
It is true that my life, like yours, is utterly inconsequential in the grand scheme of things. It is no surprise that we ultimately matter only to ourselves and those around us, the fact that we seem to be without free will has no bearing on the way we experience love and joy or pain and sorrow. This does not mean that our lives are not worth living.
Meaning is something that we have to find for ourselves. If what Pascal said is true and all men seek happiness, if even those among us who find they are too eager for the rope are seeking happiness, then we have no choice but to do so - the universe simply wills it. This fact does not make our subjective experiences of happiness any less real or valuable.
Why is it that some men are able to withstand the crushing weight of their own existence without a second thought while others are so overcome with this burden that they are driven to suicide? Why do some of us find immense joy in simply sitting and noticing what air tastes like at the same moment that others are miserable? I cannot choose to undermine the intricacies of reality that make my mind want to destroy itself any more than you can choose to be happy with the little things in life.
We ought not be frustrated by considering reality in this way. We are not in control of our perceptions and there is no reason to believe we have free will. This doesn't mean we can't experience beauty and value that experience.