It happens to the best of us: You're gliding through your sheet music when a string of cryptic notes sends you fast-forwarding through the song, desperate to make some sense of what's on the page.
It's easy to ignore rhythmic notation, because many pianists get into the habit of mimicking rhythm by ear; and while this is an excellent musical talent to possess, it can create a gap between your pitch-reading and rhythm-reading abilities. You should make it a goal to keep your reading balanced, and prevent this gap from widening.
See how well you're doing with rhythmic notation, time signatures, and tempo commands: Take the Rhythm & Tempo Quiz.