This is so true, but sadly some people still even if it happens to them, instead of getting kind and helpful to not let anybody else go through that, they become bitter and they like to let other people suffer like them did or worse with the excuse that if they did not have anybody for them, why they should help others now. So sad! 

And also, a lot of people do not like to help others at all, even when they can really help, because they do not believe the other what the other person is going through, but sooner or later their time will come, and they will feel how it is to feel alone, with nobody to help even when those people can, and when nobody will believe them or understand them as they did with others before.