I think I got 100 score in test at school when I was in elementary school. I was really good student in elementary school. And at that time, I feel really good. Then.. I have no 100 score in school...^^;

I think I got 100 score in test at school when I was in elementary school. = got a 100 score on the test

I was really good student in elementary school. = a really

And at that time, I feel really good. '

Then.. I have no 100 score in school...^^; = Now, I don't have a 100 score anymore.