Do you know the Greek letters in order?

I only know them by Sorority and Fraternity.   Delta Sigma Nu to you too!!!   and a Phi Betta Cappa.  

I'm better at singers like Cobain and Frank Zappa

(I made it rhyme for you)

Without looking it up:

alpha, beta, gamma, delta, epsilon, zeta, eta, theta, iota, kappa, lambda, mu, nu, xi, omicron, pi, rho, sigma, tau, upsilon, phi, chi, psi, omega


Is that all of them? I studied Ancient Greek in college and learned how to write all of them. I should know them by now!

Yes. You have to learn them if involved in panhellenic association.

They are indeed important in science etc., but generally you don't need to learn the Greek alphabet specifically for that because the paper or text-book should define them locally, though some are universally used for particular values.

Pi is the obvious one, but among others lambda is conventional for wave-length, delta used in calculus for the differential signs though the Integration sign is the Old English elongated 'S' (effectively standing for 'sum'); alpha, beta and theta are common in trigonometry.