If you fully understood what the medical effects of loving are you would try to love everyone and everything in the universe

 In other words "When you hate someone that hate begins to kill your mind and body."

But, when you love someone "This tends to increase your mental and physical health measurably!"

So, if you understand fully the physiological effects of loving yourself and all other beings in the universe, just get prepared to live to be 100 or more.

But, if you are filled with only hate for yourself and all others you might not make it to 20 or 30 years of age at most.

So, loving is in your enlightened self interests if you want to stay alive and sane.

By God's Grace