I don’t think anyone fully understands the way our brains work, no matter how much research, nothing is fully explained. Cap may be under stress, worry. Friede tends to have the dream of him falling off the ship numerous times when he was under too much stress or worried.
Cap just doesn't understand, it's been a whole year since that event and the ship turned out just fine, minus repairs to the balloon...why is the dream creeping up on him again now?