whats wrong with my headlight

ok, so my drivers side headlight stopped working the other day. I figured it was burnt out and ordered some new GE nighthawks or some such thing from amazon. But just the other night the light came back on, for that one night. I just looked at the wiring chart and it looks like the passengers side wire goes through the drivers side. I dont understand why the passengers side would work and the drivers not, unless its burnt out, but it apparently is not....

any clues?