Here is something I learned going through AeroMed when I was a brand new flight school student. I didn't see you could really mean: I didn't see you!
We have all pulled up to an intersection and looked left or right, by only slightly repositioning our heads, upon not seeing anything we begin to enter the intersection only to spot something from the corner of our eye and stop. When we look directly, we observe a vehicle that we previously didn't see. This is because we have a blindspot in each eye. This blindspot is corrected with binocular vision. Basically, where the optic nerve attaches to the back of the eye, there are no light receptors. This is the blindspot. But, because we have two eyes with overlapping vision, we never notice this blindspot. When you only slightly turn your head to look, the bridge of your nose COULD block your view of the object being viewed by the one eye. If the object being viewed falls into the blindspot of the one eye and the other is blocked by your nose, then you really didn't see the object. The blindspot is only five to ten degrees wide and therefore, a small object (such as a motorcycle) viewed at a distance, could be completely in the field of view of the blindspot. Just something to think about.

I agree with others: defensive driving and good equipment (protective and motorcycle) will reduce your risk for accident or injury.

Michael