What does loneliness mean? What is it like? Can everyone feel it?

There were no signs of trouble when you returned home from your daily annoying routine (study/work). But how can a person calmly pass by a situation where grown guys pester a little girl? She looked so fragile and uptight! Still quite small... Oh, if only you were an indifferent person and could pass by this picture. But unfortunately this is not about you. You decided to intervene.

But when you already approached, the guys for some reason left her alone and finally you were able to see her dead blue eyes. Then you experienced loneliness. It doesn't belong to you. You felt her loneliness.