You just learned it Spartan? Congrats! Welcome to the fantastic world of chord theory. The best guitarists historically have an innate understanding of chords and chord structure. Not necessarily because they studied them, but because they were constantly listening to what would make a song interesting.
Most rock songs go "1, 4, 5" ("I, IV, V") or maybe even "1, 4, 5, 6m." The best guitarists bastardize those chords into something crazy.
For instance, Sleepwalk could easily be written in 1, 6m, 4, 5, (C, Am, F, G). But Setzer's version opens with C, Am7, Fm7, G7. That's insane!
Have fun figuring stuff out! It's a fun, fun process of constantly learning new 'crazy' chords that sound right together.