I'm not so much afraid of dying as I am afraid of leaving my dad and my brother all alone

Also my kitty.
Non-existence scared me when I was a kid though,
and I really think that kind of thing isn't something kids should be encouraged to think about, just let them be kids for a little while and worry about dying later!
Or if a friend or family member dies, THEN is the time to start thinking about mortality. Not when you're just running around in good health.
Even when you aren't... obsessing over death is never a good thing.