My girls got their first bikes this past Christmas and we are having a great time riding as a family a few times a week. The trail is not perfect. There are ant nests, palm tree leaves (about 7 ft. long), and lots of cracks and uneven pavement. They have fallen a few times. Nothing serious, but they learned very quickly how to navigate the cracks.
That got me thinking. If the path was smooth and perfect it would be much easier for them to ride their bikes, but they wouldn't know how to navigate the cracks and uneven pavement when they encounter them in the future - and they will encounter them. Such as in life. Let them fall when the stakes are low so they have the skills to navigate the cracks of life when they grow up and the stakes are much higher.