@tatjanastan, KARMA is really simplistic subject and most effective too, but for sure many people hold the lack of understanding about the Concept Of KARMA. And by that i mean, what you do, you will get in return. But the concept get moulded when we attach past life with it, means, if somebody is facing adversity some people say that it's their past deed instead of helping them holding kind words towards them.
Wishing you an great day and stay blessed. 🙂