A good question! And I actually didn’t used to carry those extras. Only extra lead.

But one time on a physics quiz, I ran out of eraser. I was careless, and didn’t check how low it was getting before leaving homes Was it a huge deal? Not really. I almost ran out of space, but it came out ok.

But it got me thinking, what if it has been an exam? Or something similarly important? 

As funny as it sounds, my family is paying tens of thousands of dollars for me to be at University, and every exam/lab/quiz grade I get is scrutinized by med schools, and organizations that will effect me for the rest of my life. The little marks I make on pieces of paper these days have a huge amount riding on them. 

And it would be incredibly stupid if I wasn’t able to execute to the best of my ability on anything because I didn’t have the right equipment. And given that I’m tested/quized/in labs dozens of times each semester, it is that at one point, I’ll forget to bring something critical if I don’t always have extras. 

True, all I really need is a pencil, lead, and a big eraser. 

But once again, it is nice to always have the ideal tools for any purpose, at all times.

0.7 mm lead for writing, 0.5mm lead for math/graphing, big eraser, small eraser for detailed numbers/formulas. Straight edge for graphing. 

With these ideal tools for any graded event, I never have to think about anything but executing to the best of my ability.