You can see the effect all the down to something as small as 4 friends who have met once a month for 10 years eventually having to break up due to life getting in the way, and the feeling that not only is it going to be sad to not have these meetings any more but the feeling that there is some sort of almost-concrete entity that is somehow being hurt and needs to be defended, as if there is some obligation that has been created independent of the four participants that is being violated beyond the mere summation of four people's personal feelings. Humans build these structures readily and often defend them beyond what rationality may suggest.