I think to consider the risks and be aware is healthy, but as has been said, don't become fixated on them.
I get butterflies before flying full size and my r/c models, but once the engine is going, checks being done, my mind is focussed.
Driving home last night I nearly had a head-on at 60mph+; I just rounded a corner and a car is on my side of the road doing an overtake. Less than a second to react, no point braking, just tuck myself into the verge.
Not much you can do about that.
Had a suspension failure on my car a year or so ago. That made me think. I didn't crash it, but had it happened a mile or two earlier, I could have gone off the road and down a big drop.
Not much I could do about that one either.
When flying you've probably got more time than driving, if something goes wrong. Engine failure, even after take off, you've probably got five or six seconds to recognise, react and decide. Head-on as above, suspension failure and into a tree or whatever; not a chance. Structural failure in aircraft, not a chance. Likelyhood very small in non-aerobatic flying.
I'd rather be flying.