who tells it is pain?

Let's not go after things just because they are more tough to pursue or just because there is more pain in it and because more people won't pursue that path. Lets pursue a goal because we can have the pleasure of travelling and because that is what we constitute.

By the way, who tells what is 'pain'? How in the world one can define what is pain? Is it the difficulty that is called pain or is it the temporary feeling of high level of discomfort that makes us call it 'pain'. who tells what level of discomfort is the minimum to call it pain?

Md. Ali, the boxer whom the world remembers never seemed to call receiving a punch in face 'painful'. Lance Armstrong never seemed to call riding his bike is painful enough to stop pursuing the goal even in the times of gloomy and bleak future. 

Technically speaking, the 'Pain' has two components. The 'physical' and the 'emotional'. Most of the times, almost all of the times, for a common man, it is the emotional part that strikes first. The blow is severe enough for most of the people to loose interest in pursuing the 'physical' part.

The physical part will obviously difficult. Lets not confuse 'difficulty' with 'impossibility' here. The level of uncertainty will be always there with any unaccomplished physical work. The uncertainty has to be converted into certainty. This requires the desire to succeed (a desire 'not to fail' is not sufficient), guided work and time.

Never to forget that pain is temporary and pleasure that comes from pursuing a tough task is long lasting.