This world is arranged in a certain way, and there are Higher Laws by which everything that happens is subject. Ignorance, misunderstanding or rejection of these laws does not nullify them.
We can say that Life is built on the principle of a school where we have to learn wisdom: to know the laws of life and live in accordance with them to enjoy every moment of life.
We live in a closed system in which all its parts are closely interconnected with each other and have mutual influence, so nothing is accidental, and nothing goes without a trace. What you emit is what you get.
As you sow, so shall you reap. All that comes back to you is what you do to others.
Folk wisdom. The Golden rule – "do not do to others what you do not wish for yourself" - is built on the understanding of this.
Why is it hard to understand? Because life here has a duration (time, inertia) and "bestowal" does not come immediately.
When you launch a boomerang, it needs time to fly away, reach the end point and come back; and while it's flying, other boomerangs launched before are coming back to you. As mind (in most cases) can't notice this cause-and-effect relationship, there is no understanding that nothing happens by chance.
Everything is interconnected and natural.
You need to understand that problem happening to us is not a punishment from God (Higher powers, etc.), as a result of a breach by us of these Divine laws.
In other words, I was the cause of the trouble myself.