The mother is able to sense the pain of a child even if he lives in the opposite end of the world because the child was once connected to her with the umbilical cord. Even though the cord is cut, the connection still exists and this is a basic physical connection. Just like the child and the mother, every particle that was inside you and changed form and separated from you has the ability to communicate with other particles. The strength of this connection depends on the purity levels of your body. It is like a transmitter and receiver, the transmitter sends the signal but if there is a lot of dirt on the receiver then it will be unable to receive it. The dirt in case of your body is your thoughts—positive and negative. The thoughts form a cover over the body and do not allow it to communicate with that, of which it is a part. In order to communicate, purity is essential.
At many occasions I have seen people consuming bhang and getting intoxicated in the name of Shiva saying it is a prasad of the Lord. This is a very wrong notion. Madh (intoxicants) is the ahar of nisachar, and it literally translates as dulling of the senses. Alcohol is like dust, intake of which dulls the senses and makes communication ineffective. Similarly happiness or sadness are like dirt which block the communication channel. You must have heard of cases where people get a heart attack owing to extreme joy or grief. Joy and grief need to be kept in balance. You are not experiencing any happiness, but others think you are or if you have to get angry, you display controlled anger where you are not angry but the other person thinks you are angry. If today you are very happy with getting something or are sad about losing something then start getting detached from it right now because both happiness and grief will give you a lot of pain as they are contaminations within you. Any kind of impurity hampers the communication between two particles and so balance is a must.