Of course, youth means a cavalier disregard for the perils of life, more aggression, oodles of testosterone (if you're a bloke) and general derring-do. These things are good for winning races and performing stunts. But they're also good for putting you in a gravel trap, or into the side of a U-turning Uber Prius.
At the other end of the scale, things like eyesight, muscle strength and mental agility can start to go once you get old. Trying to keep your 35-year-old self's pace when you're 55 might lead to trouble – do be aware of your declining powers, and mitigate them if possible, before they start to affect your skills.