I have only been flying for 25 years, but in that time I have
experienced the deaths of many friends and acquaintances.
After getting my PPL, I got heavily involved with aerobatics and warbird
pilots. The aerobatic pilots have passed at the rate of one or two every
year.
The first couple had me asking the same questions.
In discussing it with one pilot friend who had been around for awhile,
his matter of fact response of "When your number's up, you're number's
up" has stayed with me.
I still feel the loss and I still wonder why, but I do not dwell it.
As others here have said, remember the good times and the joy it brings
to you and pilots and friends you share the activity with.
Read all the accident report you can and run "what-if" scenerios through
your head when you are looking for things to do.
The more prepared you are, the better equipped to handle a situation.
There may come a time when even that won't be enough.
The most important thing to remember is, never give up!

Jay, sorry for your loss. My condolences to all.