How to be unlimited?

Once a teacher was teaching about the life to his students near a lake. He asked one of them to take a glass and bring water from the lake, after he brings the water, the teacher added some salt into the glass and asked his student to taste it. He obeys and quickly spit it by saying that "Sir, it is very bitter in taste". The teacher says "ok, now take the whole bag of salt and pour it in the lake and then get a glass of water and then taste it". He obeyed, the teacher asked "now how is it?".
The student replied "now it is sweet", the teacher said "how it is possible, you pour some salt in the water in glass and it became very bitter and then you pour full bag of salt in same water that was in lake and it is still sweet. He added " it is neither the salt which changes nor water, the only thing changes is the area of the container. When it was a glass with small area that's why a small amount of salt affects it but when it was a lake, the area became wider that's why the whole bag of salt can't make it bitter".
Moral:
Similarly, we all have to deal with the bitter people's in life but it is all our choice to let them affect us or to ignore them. It all depends upon how wide our prospective or mind is. You can react on someone's criticism and fight him or you can ignore it and learn from it.