A cup and a lake

A teacher came to her student, Tom, who has been looking gloomy lately and asked, "Tom, Why do you look so sad? Isn't the world such a beautiful place? Where has your smile gone to?"
"Teacher, I have a lot of problems recently and it's very hard for me to keep smiling. It seems like the problem will never end." Tom answered.
The teacher smiled back and said, "Tom, bring me a cup of water and two handful of salt, and let me cheer you up."Tom went with low-spirit and brought back what his teacher asked him to do.
"Now, try to put a handful of salt into this cup of water," said the teacher."Then, try and taste the water." Tom did and he grinned because the water was very salty."How does it taste?" the teacher asked."It' salty and my stomach feels queasy" Tom answered with a grinned.
The teacher then brought Tom to a lake nearby."Take the remaining salt and pour it into this lake." the teacher commanded.Tom pour the remaining handful of salt into the lake, without a word.
"Now, try to drink the water from this lake," said the teacherTom slowly kneel down and using both hand forming a small cup, took the water from the lake and put it into his mouth.While he was drinking, the teacher asked "How does it taste now?""Fresh, it's very fresh" said Tom while wiping his mouth."Do you taste the salt that you poured in just now?" the teacher continued "Not at all" Tom answered.
The teacher then said, "Tom, every problem in our life is like a handful of salt. It's just as simple as that.Much or little pain that you experience in life has been determined for you. It is fix, it will not more or less pain. This applies to every human being born in this world. There's no one, even if he or she is a guru, can be free from pain and problems in life.
But, the 'saltiness' from the pain that you experience is very much depend on the size of the 'heart' that contain it. So, in order not to feel miserable, stop being a cup. Expand your heart to the size of the lake."

"A person's world is only as big as their heart"
-Tanya A. Moore-