Looking on the internet deeply has found these results:

don't know why I have a headache is the most popular phrase on the web.

don't know why I have a terrible headache 10 results on the web	don't know why I have a headache 1356 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
It doesn't look like this phrase is very popular! The search could not find any examples on the internet.	Jan 5, 2013 ... It was funny because there was crashing and banging happening in the background and he was saying, "I don't know why I have a headache." Of course he knows why he has a headache! He works in a really really noisy�... b� zh? w�i sh�n me ? w? y?u di?n t�u t�ng ? I don't know why I have a headache . ????????????? w? zh?n b� m�ng b�i ? t? z?n me n�ng zh� y�ng ? I don't understand why he behaved like this. ?????????? zh� g� sh�r�... Jan 11, 2007 ... ... and it's still the same....the page cannot be displayed always appear..but there is an internet connection but i can't connect..don't know why??i have a headache already thinking of so many ways to make it work...so please�... Aug 18, 2014 ... �I just feel terrible�, said the man to his physician, �and I don't know why. I have a headache and my whole body just hurts�. �I see�, commented the doctor, �would you bare with me for a moment, I have to take a quick look at�...

don't know why I have a terrible headache

10 results on the web

don't know why I have a headache

1356 results on the web

More popular!

It doesn't look like this phrase is very popular! The search could not find any examples on the internet.

Jan 5, 2013 ... It was funny because there was crashing and banging happening in the background and he was saying, "I don't know why I have a headache." Of course he knows why he has a headache! He works in a really really noisy�...
b� zh? w�i sh�n me ? w? y?u di?n t�u t�ng ? I don't know why I have a headache . ????????????? w? zh?n b� m�ng b�i ? t? z?n me n�ng zh� y�ng ? I don't understand why he behaved like this. ?????????? zh� g� sh�r�...
Jan 11, 2007 ... ... and it's still the same....the page cannot be displayed always appear..but there is an internet connection but i can't connect..don't know why??i have a headache already thinking of so many ways to make it work...so please�...
Aug 18, 2014 ... �I just feel terrible�, said the man to his physician, �and I don't know why. I have a headache and my whole body just hurts�. �I see�, commented the doctor, �would you bare with me for a moment, I have to take a quick look at�...