It’s because they’re curious or they get peer pressured into doing it to “fit in.”
Answer:
Cells divide so living things can grow. When organisms grow, it isn't because cells are getting larger. Organisms grow because cells are dividing to produce more and more cells.
By the way the question tells me I must think that it might be perspective because you need a perspective to bring things to life.
Most scientists don't used the word law because that implies it is infallible but generally scientific laws and theories are used interchangeably so true.