Yeah, that's my understanding of it, too. If you go back in time to any point in your life, you'll be exactly the same, with all the same experiences and the exact same thoughts running through your head. Every single atom in the entire universe will be exactly the same as it was at that exact moment, so of course you'll make the exact same decision.

The universe as a whole is just a huge, insanely complicated chemical reaction. Ultimately, we're free to make whatever choice we want, but that choice was what we were always going to choose.

It's like how flipping a coin or rolling a die isn't really random - if it were possible to gain an insanely in-depth understanding of all of the forces acting on the object, and you had the power to manipulate your throw to give it the exact force needed, you could have it land exactly how you want it to every time. Instead, we call the act random because it's too complicated for us to manipulate it effectively.