I didn't read all replies so if it was already mentioned sorry, I put the helmet on my daughter before we even took her out for a ride. I can't remember the exact age but she had just started standing so about 8-9 months old. At times she didn't want to wear it so we let her know that if she wanted to ride to the park or around the block the helmet had to be on. As you can imagine we had a few fits and time outs. This is no different than any other behavior correction we have had to make with her. But now she wears her helmet with no trouble and will remind me to put my helmet on for that ride around the block.