Sorry to hear of your friends accident. You always have the opportunity to NOT ride. Let me tell you about my experience.
I started riding at 13 years old. Got on the street when I was 17. When I was 23 we had our first of two children, my daughter. One and a half years later we had our son. Looking at the two of them I decided I needed to stop riding because these children had to be raised and motorcycles made the responsibility of raising them risky. If I had a bad accident I might not be able to raise them.
As my children grew my son asked me about the pictures around the house of motorcycles as well as a few hare scrambles and trials trophies that I had won when I was younger. He asked numerous times if he could have a motorcycle and I always nipped the question in the bud. I told him he didn't need to ride a motorcycle because they were too dangerous.
At 20 years of age, driving back to college from a weekend at home my son was involved in an automobile accident that killed him. Two weeks later I had my first motorcycle since the children were born. I won't stop again unless I physically can't get on one.
You can't totally control what is going on around you! You can be more in tune with your situational awareness and hopefully it will help keep you out of the way of trouble although you'll never be totally safe.
Today my only regret is that I didn't keep riding after the children were born and introduce both of them to motorcycling. I think my son would have truly enjoyed it but I never gave him the opportunity.
So, stay alert, be careful, anticipate poor drivers, ride your motorcycle and enjoy the life you have.