Last December, while out on an early morning walk, I tripped on a bump in the street. It caught both of my feet at the same time, and I fell forward fast. I instinctively used a Judo front fall and landed safely. No injuries except for abrasions on my hands and a bit on my knees. It could have been bad; the street in question was very rough, with lots of little rocks mixed into the asphalt, and I use my hands for a living. Not knowing how to fall properly could have resulted in a broken wrist(s), arm(s), shoulder or facial injury, etc.
I haven't practiced Judo since 1979, yet that breakfall was automatic. All that time we spent practicing breakfalls at the start of classes really ingrained them into the nervous system. IMO, breakfalls are the most important aspect of Judo that I learned, and they're especially valuable as you get older.