What or why is more important?

Imagine, if you will, that you are Newton. There you are one day, innocently hiding from the wife and her inexplicable urge to have you take out the garbage, grease the carriage wheels, tramp down the front lawn and finally put a roof on the house. Without warning you are plunked on the head by a worm infested apple.
Well, now your nap is ruined and you are in for a few minutes of chewing out because now the laundry needs to be done. Seems like you might as well make butter cream out of sour milk, so you come up with a reason for the apple to fall.
"We have this thing called gravity" you say. "It is everywhere. It is on the earth and in the atmosphere...why, it is even in certain situations."
"What does it do?" someone asks.
"Why, everything." you reply. "When an object enters airspace by some means, unless it has support the force of gravity shall force it to return to the nearest source of support which is most likely the ground. This gravitational pull prevents some things from happening that might be construed as a negative...for instance, without gravity you would fall away from the surface of the earth and go hurtling through space to meet a grisly death as you leave the oxygen-laden atmosphere of earth."
"Oh, cool," comes the reply. "I like gravity. Why does it work?"
And here Newton would have to channel his mother. "Don't ask why. Sometimes things just are."
This, of course, was later discovered by Michelson when he experimented with aether shift. His theory was that if c=v*wl and the earth moving away from the star caused wl to equal wl+x whereas when the earth rotated towards that same star then wl=wl-x where x = rate of movement in relation to the star then the light waves moving through the aether would naturally change. After all, light is simply electromagnetic waves moving through the aether, and the color is determined by that rate of speed. When he discovered there was no difference, he had the following explanation; "It just works and we can't explain it."
Fair enough.
So what means more; knowing that light works and how...or knowing why.
Not knowing why things work has caused much of Newton's work to be demonstrably false...exceedingly interesting since much of science we have that DOES work is based on Newtons laws...which worked, but were false in reasoning.
Huh?
So if we don't know why something else works...say, electricity...is that more important than knowing how it works?
The answer is not as simple as you think. The real soultion is as follows. Oh, wait, 10 o clock. I am going to bed. I know how, I just don't know why.