My big toe wont bend downwards. Is that normal or am I just inflexible?

Not normal. There is an expected range of motion to the great toe and bending downward past parallel to the foot is expected. There may be pathology in the joint or surrounding structures or arthritic changes to the great toe joint.
You may. Have arthritis in the joint that is restricting the range of motion. Possible flexer tendon problem.
It's abnormal. You should be able to bend the big toe (called the 'hallux') downward. It if far more important to be able to bend it upward though.