An analogy would be polishing a surface.
Best comparison is a car engine.
The pistons, rings, and cylinders in a new engine are not perfectly mated, and will not produce the optimum power, until the parts have worn together.
Once the parts are porperly broken in. No further problems will occur for hundreds of thousands of miles.. With a good setup, and proper oil changes, the engine could last a million miles...
IF the engine is taken apart, and reassembled.. it would need a little break in time again. to become optimum.
Hope this is a good enough analogy.
Naturally anyone can pick holes in it.. so feel free to do so.. I won't worry about it.