I defined this drama "just human" because that's how I see it. Because that's the adjective that fits best.
This story depicts the many facets of human beings and I'm going to list the reasons.

I want to start by saying that I rarely write a review, because if I do there must be at least one of these reasons: 1. It has to be a great story that impressed me positively or 2. It has to be a story that made me feel deeply sad about something/disappointed.
This drama gave me both.

The story is very well thought, I really feel like praising the screenwriter/s and the director. The story of the main couple is just delicate. Two teenagers portrayed with all their true emotions, difficulties, fears, hopes. They look real, spontaneous. The events just flow perfectly and with realistic dynamics.
The way they build their relationship is through hard work, collaboration (especially after Xiang Hao Ting gains Yu Xi Gu's trust). It's cute how both fall in love with each other and slowly start to know their weaknesses and faults. It was harder for Yu Xi Gu because he was very introverted, due to all of his life's challenges and I can't blame him at all for that. He was just defensive and only a stubborn, crazy guy like Xiang Hao Ting could reach his heart. He was a boy full of energy who put his all to achieve anything he wanted and I admired him for that. His character development was splendid.
Sexuality, desire, feelings, are depicted just as a teenager would live them. Those few scenes fit perfectly with the dynamics and weren't forced at all.

The second couple was cute too, and I can't say it's not common to see age-gap couples (and who am I to judge if there's true love and dedication?). Sun Bo Xiang was a very good friend too and I appreciated his character a lot.

This drama made me the spectator of something extremely real. Social problems, family issues, the conflicts of young boys who yet have to build their future. That's how life is for the majority of people.

What got me deeply into it was the display of emotions (anger, sorrow, sadness, joy) because the actors did an amazing job and expressed it all with heart + another praise to the sound designer for the soundtracks. The music was so beautiful and emotional that, for me, it had a huge impact on the scenes.

I cried a lot at the end. I also felt a bit disoriented with the flashforward, it took me some time to understand what was happening and what fate was reserved for Yu Xi Gu. Many people say it's not fair (yeah you're damn right) and other say they skipped the last episode. I didn't expect all that pain and it left me hollow. But after thinking about it, I came to a conclusion: life can be like that. You can put all your effort into something and then it can slip away from your hands. Happy endings don't happen for everyone, even for the best, hardworking people. Sometimes it's just fate, or bad luck, however you want to put it. I know people who lost relatives or their partner in similar, unfair, circumstances. Life can be like that too.
"You naively think that something will be there forever. But then you understand it's a lie. That one day, it could not be there anymore". So, what it conveyed to me was this: live your life to the fullest, cherish every moment and never stop believing in your goals.
I firmly believe that this drama deserves a lot more attention and love.

Last, but not least, give a damn Oscar to Wayne Song.