People's dreams are made out of what they do all day. The same way a dog that runs after rabbits will dream of rabbits. It's what you do that makes your soul, not the other way around.
However, I wasn't very good at the sciences, or didn't have a lot of help in the sciences or something but certainly didn't set science for my A level. And when I came to take my A levels I didn't get a good enough result to go to University.