So here's the good news:
YOU DON'T HAVE TO LEARN THIS PERFECTLY.
More good news:
YOU DON'T NEED TO LEARN THIS PERFECTLY
However (comma):
You ought to learn it pretty well.
In fact,
You should learn it quite well.

But if you want to be perfect someday,
You must learn it.

Ok, what you just saw was what we call EXTERNAL and INTERNAL motivations.

Oh....GIVE ME A BREAK. Is this a social methods class?

Well, you could call all language a social method. True?

I mean it...Give me a break...or.. Is this serious?

Seriously. HAVE TO and NEED TO and OUGHT TO and SHOULD mean you are taking directions from something outside yourself. But MUST means you are deciding to do it yourself.

You cannot be serious....You are serious. Well...Is there ANY good news?

The good news is -- strange and varied as they are -- they all keep the same person-forms and verb tense forms.  Ok let's start clicking. John wants to take home the Gold Medal. Therefore:
race must can John win the
 ____ ____ ____ ____ ____.