When my daughter was just learning to ride, she went down the hill into the park and forgot how to use her brakes. She had a high speed head first dive into a rockery. Her helmet broke, her head didn’t. My kids will never ride without them.
Same park, different day, son still had his bike helmet on when he fell backwards off the top of the slide (the big one, that he shouldn’t have been on). Helmet broke, kid didn’t.
I hate that park.