dent in the wheel

Pat said:

I went to go ride this a.m. and noticed a diagonal dent in the side wall of
my wheel. Not only do I not know how/when it happened, but I need somebody
to tell me if I can just ignore it. How important is this kind of thing? The
brakes still work fine....

Watch the area for cracks and keep watch on the spoke tension balance, especially in that area. I rode over 1,000 miles on a tour with a similar situation. I watched it carefully... maybe it was on my mind to much. When I finished the tour in Portland, Maine I replaced the rim even though it never showed a crack or made any change in spoke tension.... I just wanted to remove the potential problem from my mind.

Pat said:

I went to go ride this a.m. and noticed a diagonal dent in the side wall of
my wheel. Not only do I not know how/when it happened, but I need somebody
to tell me if I can just ignore it. How important is this kind of thing? The
brakes still work fine....

Generally not a good thing, but a good close up photo will be needed
for anyone to give you a reasonable answer.