President Obama’s National Address to America’s Schoolchildren Which claim made in the speech is supported by reasons or evidence?

"The story of America isn’t about people who quit when things got tough."

"You might have to read something a few times before you understand it."

"You don't hit every note the first time you sing a song."

"You're not a varsity athlete the first time you play a new sport."

"You're not a varsity athlete the first time you play a new sport."

Explanation:

Varsity athletes have usually trained for years to earn the right to become athletes at a university level and even if they only became athletes at varsity level, they did not get selected to be varsity athletes from that first time thy played the sport.

They had to play a lot more times to be chosen to play at that level. This goes to show that the first time you play a sport, you cannot be a varsity athlete.

Of course the President meant this figuratively in that you cannot be as good as a varsity level athlete the first time you play a sport, but even this is still supported by reasons and evidence because you need to have practiced for a while to get to that level.