Give my children a better answer than "Because" when they ask, "Why?"

I was always asking questions when I was a kid and have memories of either getting unsatisfying answers, i.e. “because I said so”, or at after a certain point, my dad would just ignore me. Or, for full disclosure, would ignore my persistent, “Whatcha doin’?” questions because he felt that if I just opened my eyes and saw, of course I would know.

Sigh.