I've been convinced about the perils of wrong-way riding (I was originally taught it was *safer* to ride against the traffic). I still do this for a very short distance on one small portion of my commute where crossing the street is impossible due to a barrier fence, but I am much more careful about it. Hopefully on my new commute there will be no reasons to ride the wrong way.
I've also learned something about the debate over bike lanes. I used to think they were the best solution for all situations, but now I know that isn't always the case.