It's a concept in quantum mechanics.
The question of free will always comes down to the question of causality and determinism.
Therefore, it really doesn't matter if there is free will in our lives as long as you can close your eyes, throw your hands in the air, have fun, and make it through...
It matters because the self rests in the space left by a break in the causal chain. The question of responsibility relies on the ability of the individual to be a breaking point by conscious decision. And so it comes down to the nature of consciousness and what it means to be aware.
If it turns out that I have no real choices then the house of cards falls to the ground.
edit
Suspension of disbelief is ok for the rollercoaster but not so much for the contemplation of existence.
Edited by ProtoTypical, : No reason given.