My personal philosophy for riding a motorcycle is this:
Q: If a motorcyclist and a car get into an accident, who's fault is it?
A: It's the motorcyclist's fault.
This is my application of the principle of 100% responsibility. I got back into riding at 37, and took an advanced motorcycle safety course, to "refresh" since I already had my license. It was really good. Their section on "threat detection" really landed for me. They had a simple exercise where they played a video taken in traffic. It paused every few seconds, and they said "What's about to go wrong here?" What I realized is that there is 1,000 times more information available to me than I was availing myself of when driving a car. Cars are so safe that you don't really need to look all that hard for things that could be about to go wrong.
When I ride, my attitude is that it doesn't matter what somebody else should or shouldn't do, it only matters what he could do. In cars it's safe to make assumptions based on the rules of the road. On a motorcycle it is only safe to make assumptions based on the laws of physics. I assume that I am not seen, and that every car that is within striking distance might be about to do the worst possible thing for me. Then I watch for them to do it. Driveways, side roads, the other lane, all of it. I admit I don't check behind me as much as I could.
When I first got back into riding, I was terrified everywhere I went if there was another car anywhere near me. After that course, and like 1 day of applying what I learned, it was suddenly like the entire world was in slow motion when I rode. What I have found is that when I am doing this, I never even have close calls. There is tons of time to avoid somebody doing something that you are expecting them to do. Bikes can stop so fast that these aren't even emergency stops. Yes a car behind you can't stop that fast, but I make it a point not to have cars close behind me in the first place.
The only close calls I have ever had have been when I slipped into "car mode" and expected people to do what they "should." I do make it a point to minimize how long I'm beside another moving vehicle, and I do avoid driving in dense traffic as much as possible. Motorcycles and commuter traffic are a bad combination. Fortunately, all my motorcycles get hot as hell if I spend any time at all moving slowly or stopped, so I have an extra incentive to make sure I'm not in that situation in the first place.
In 13 years since I got back into it, I've had 2 accidents which were both my fault, resulting from me taking risks that I knew I was taking. No meaningful injuries either time. I was dressed appropriately one time, and that was part of the decision to take the risk (single vehicle accident, I leaned too far). The other time it was 10 mph. Honestly I was in shorts, a t-shirt and Tevas - and a helmet. I tumbled, but didn't get a scratch or a bruise.
I may well end up a vegetable tomorrow, but my experience so far is that this expression that has an up-side: "People who are looking for problems usually find them."