I echo the others suggesting a potential concussion; I went riding w/ an old gf once and she went down sans helmet. Her asking me where she was and how she got there (she was visiting from out of state) for the next three hours+ had me pretty worried until a dr. checked her out and confirmed the concussion.

Foam cracked all the way through = new helmet. Maybe see if you can send it in for partial credit, or something.

Heal up fast!