Because new things are always attractive.
The longer we live with our relatives, the more we assume that they must fully understand us. I always thought my parents would have to understand. The fact that I didn't like carrots has been around for many years, how could they not know? Because they no longer care about me? This is a very malicious thought - if you ask your loved ones to understand you so much, why don't you understand that they only do those things for a good purpose?
Be honest, you and I are grumpy with relatives because long-term relationship allows us to get angry and that we know there will be no "punishment". As for strangers, try to get angry and the consequences can be very unpredictable: a punch, an insult or even terrible things.
Of course, no one wants to behave like that to their relatives. In our hearts, we always feel guilty that we were wrong when we got angry, but then everything will happen again. The problem is not the carrot, the stain on the shirt, but it is because we blame our relatives for not understanding. And everyone considered that unacceptable.
New things are always attractive.
We are bored easily, we do not like repetitive things, and eating a meal, again and again, is almost impossible. Going to work, dealing with your boss or other relationships everyday make you feel tired. And sometimes, you get angry with your relatives just because you need someone to release your stress. I feel bad to say this, but old things always make us feel boring.
In our eyes, relatives are immutable: Even if you go far, whatever you do, they are still there. As people often say, "No matter where you go, remember that there is always a place to return." We don't acknowledge that statement gratefully but think it is an indispensable thing in life. We overlook the close relationships. Human always wants to conquer new things, when loved ones belonging to our "ownership", why do we need to keep it tight?
What about strangers? If you just met a guy, maybe he poured a whole cup of water on the table on your shirt, you could still laugh. We tell ourselves that the new attraction is worth exchanging, a shirt is not that a big deal. Although it is certain that new things will become old things, in that first time of acquaintance, good behavior is a necessary condition to attract someone.
Precautions against strangers.
Sometimes, being cautious in unfamiliar relationships makes us more kind to strangers but forgets that relatives also need to be treated like that. Living in a society that needs to be wary of everything, I do not dare to speak loudly to new acquaintances, avoiding expressing myself in a negative way to reveal weaknesses. We slowly put on a smile, a calm, a calm look, a sharp look. I see such a story in a work-place very much, even in this case, the kindness is not what I feel when the back of it is filled with other attempts?
Anyway, avoiding clumsy conflicts is essential. In relationships with relatives, there is nothing for each person to hide or avoid (unless it is adultery) - we feel comfortable expressing ourselves, including bad things. The longer the relationships are, the longer they know each other, the more likely they are to behave badly, exasperated, and even become violent. That is a sad thing.
And then you have nothing.
The emergence of social networks, of the virtual world, also makes us leave the spiritual values of the family. That has exacerbated the "selective kindness" that family and relatives always stay at the lower place. Perhaps, when regret came, it was too late. You don't just throw away your grumpiness and frustration, but sometimes throw the relationship out the window.
It's not worth it. Remember that family is the only thing that matter, that will be by your side and always support you for no purpose. One time my parents told me, "Even if this world is against you, we will always be the one who supports you."