Does anyone know how to get the hint videos that appear in the world 1 castle?

I know you have to buy them with the big coins, but how do you make them available to buy? I'm in World 7 and I have almost all coins and there are still lots of videos that have "??????" and don't let me chose them. There must be something special you have to do to make them appear.

Thanks.

 

you have to beat the game and collect all the coins including those at world 9 so that you could unlock all hint videos at peach's castle.

 

Nope, not that. That is a level walkthrough if you suck. Yup, I've had that come up a couple times but thats not what I'm talking about.

In world 1, the very first level (if you call it that), the princess castle.. there are lists of Hint Videos. I just don't know how to make them appear. If I had to beat the game to make them appear then how come some appear and some dont. If that was the case wouldnt there be no videos until I beat it? Also if you had to complete the game and get all the coins wouldnt that defeat the purpose of having the videos? Why would you need a video on how to find a star coin if you already have it.
Kinda weird if thats the case.

For example
1-1 super skills is there
Then ?????
1-2 Inifinate 1-ups is there
Then ?????
1-3 Super Skills is there
1-castle Super skills is there
1-5 super skills is there
2-1 Star Coin is there
Then ?????
2-2 Star Coin is there
2-2 Super Skills is there
Then ?????
2-4 Secret Goal is there
... and so on. some pages are missing quite a few.

World 1 and 2 and most of the other worlds I have all the coins already.