Hi Adela,
I definitely go through phases of wondering why and how this happened. I had no idea what Leukemia really was until after I was diagnosed. I still find it strange that I even have it. Leukemia? Really? Me? Was it too many X-rays as a kid, too much partying in college, too much stress, something in the water, something else? I don't have a good answer and I doubt I ever will.
In all cases though, the experts have been very consistent in their message. They can't point to anything specifically that would cause this and have reassured me that I didn't "do anything" to make this happen. It's just a genetic mishap that thankfully has many very effective treatments. I am closing in on two years since my diagnosis. I'm still working through all of this but it is getting easier over time.
Take care,