butterfly effect? chaos theory? karma?

lesson supposed to be learnt from seeing the departure of my friend's mom
we should treasure our loved ones while they're still alive.
however many things, or each and every little simple things in life. they are complicated. they are complex. they aint simple. they are karma.

In Buddhist teaching, the law of karma, says only this: `for every event that occurs, there will follow another event whose existence was caused by the first, and this second event will be pleasant or unpleasant according as its cause was skillful or unskillful.'