it took me 45 or so minutes of progressing directly away from the start to find it!
use those minecart tracks, they make the trips so much quicker!
focus more on consistancy over speed, one mistake and your back to square one after all.
oh, and brush up on simple pattern logic like 1-2-1/ 2-1-2 / 1-2-2-1 etc to help avoid guessing.