Argh!

Physics Paper 3 today. Not to boast but I think my Physics is pretty average. I've always managed to scrap through with ninety plus considering the amount of careless mistakes I make.

Today, I flipped open the paper.
I saw a v/u against v graph.
Heart went lub dab lub dab.
Brain begins to malfunction. What is this question talking about??
Yes, yes gradient of 1/15=1/u.
*Scribbles furiously*
Oh no! I CANNOT DO THIS QUESTION!!! THAT QUESTION TOO!!! THIS ONE TOO!!!
How can I not know how to do a Physics question??!
Aaaaaaaaaaaaa! This is the worse Physics test ever!!!
I'm not that stupid!
*Scribbles even more furiously* and after twenty minutes...
Oh doom, I shall just settle with these calculations.
I know I am so wrong. Doom.

Then I hand up my Physics paper, knowing how doomed I am.
I proceeded to sitting for my Chemistry Paper 3.
After I finished answering it. I decided to give it another shot at calculating that Physics question.
In less than 60 seconds, I HAD ALL THE RIGHT ANSWERS!
22.5cm, v/u=(v/15)-1, 15cm.
NOOOO!!! What is wrong with my brain or head??!
I just threw away like seven marks! SEVEN! SEVEN! SEVEN!
Doom. That goes my hopes of getting above 95% for Physics.
When will I ever get a 100% for Physics... *dreams*
A maximum of 93% now and that is only if I score 100% in both Paper 1 and Paper 2.
Argh! I knew my Physics knowledge was perfectly fine!
And that question was not even that hard! NOOO!!!
Such a screw up. I shall dig seven marks up from somewhere. Grave or whatsoever.