Japanese man sets record in pi recitation - Boston.com

Akira Haraguchi, a 59-year-old Japanese psychiatric counselor, has publicly recited pi to 83,431 decimal places, from memory. He had to take two runs at it - he flubbed at about 16,000 decimal places, and then started over. It took hours and hours and hours and hours...

That's grit. I'm not sure what else it is, but it is definitely grit.