Good in Theory - Bad in Practice

You know those things that you talk about that yeah man that would be awesome, we should totally do it!!!  Then you actually do it and you find out that this wasn't what it was supposed to be or it turned out just bad.  Good in theory, bad in practice has been around forever.  I am currently in one of those good in theories bad in practice sort of things.  I have been reading through different articles and watching different videos on ways to incorporate more of my Crossfit into the PE classes that I am teaching.  The videos I watch all have kids of around my age group and they are all listening and watching and participating etc.  The biggest problem is that there is usually like 6 - 10 kids in each class.  In my class I have 20+ in every class and not all of them want to be there.  The typical response I hear is, I want to play basketball.  Well great, I'd love to play basketball too but that isn't going to happen right now.  The moral of this story is that doing something new is difficult.  Doing something that is new and difficult is even worse.  However, I have read through some different things and it has renewed my confidence that I can make this program work.  I noticed in my car today as I was getting out of my car for work the fortune from my fortune cookie that has been stuck in my rear view mirror for years.  "Your dreams are worth your best efforts to achieve them."  I need to remember that.