Humans are a composition of various different kinds complicated components. As such, we are way different from other creatures. We have emotions and brain- we think, we feel, we laugh and we cry.
As a human being, seriously, I think that mankind is an enigma, the more you get to know about this species, the more questions you have.
We are proclaimed as the highest level of animals as 'most' of us have culture, affections, knowledge,and rationale behind actions. We have the ability to love something and somebody that leads to selfless devotion and sacrifice.
However, being the so-called highly intelligent class, we are incredibly unpredictable, too. At this minute, we can love something to death, but at the next minute, there is a possibility for us to just throw the stuff into the drain without even realising it; totally forgot about how we once might kill to get it.
There were too many couples who declared their vows and got married out of love; though, after going through challenges in the shared new life, the feelings and affections faded away. Eventually, it follows by ugly disputes, hatred against each other, betrayal, affair, ill-assorted couples or maybe divorce.
Why humans are so forgetful? We forgot the reasons to like something or somebody. In the contrast, as time goes by, we feel like other party is changing and he or she is not the same anymore. In fact, everything is the same, it is the heart that changes.
When the heart is not there, lovely gifts turn into trashes; scrumptious meals taste like crap; dressing up became slutty.
Actually, same thing applies to friendship, too. Recently, many of my friends had been complaining that they have no more real friends as they are losing contact with previous school mates. Now all they have are colleagues, who they had fun with sometimes, and it stops with that. They said it is hard to get a real friend who really understand you or care about you anymore.
You will ask, then why not reconnecting with previous pals? Honestly, it's hard because the heart is not there anymore. Most of them are busy with work, new responsibility, boyfriend and some are even married. Perhaps, humans are only able to focus at one thing at a time, so, we chose to throw away something that was precious for us but seemed to be not-so-helpful right now- real friendship.
Well, I am sure that there will be some exceptions. Some people are really able to maintain whatever relationships till the end of their life, with a same friend or spouse, but I would say it is rare as it requires a lot of hard work. So, some people would choose to give up.
Love is really an abstract thing. You can't explain it to anybody. It is just funny that once you thought that you had a life long real friend whom you could give up everything for but after going through too much misunderstanding and miscommunication, the heart gets really tired. Next, you made up your mind to give up entirely. Then, someday you were able to meet up with him or her under a very rare circumstances, you might be glad but you won't have the thrill anymore. You won't feel sad or hateful either, there was no any special emotions. The person will just appear to be another regular friend. At last, you started wonder and sort of amazed at yourself for the dedicated you were willing to offer unconditionally last time.
You know that you will never 'give' anymore.
In short, I think any forms of relationships need a lot of 'give'. However, people started from 'give' to just merely 'take'. That's just so human nature. We are all selfish jerks.