Your parent may know, or may not know. No, i don't really know. But if they barring that down for the 40 years, its they die about another 20 years later, you are still taking your exam.

I have heard, someone does about 20 years taking tests to stay indoor. 

I don't really know your own program, you mean the undergraduate double degree or one MCAT? You can take 20 years?

If USMLE 1 and 2 and 3, in case, ...that is to give a support? 

40 years.

...Movie: Good Will Hunting, how old is that age? 

I personally don't think you gonna pass any USMLE 1 or 2 or 3 within 40 years. You forget every undergraduate class, so I assuming its Ｏｎｅ　ＭＣＡＴ．