I think i just had my own understanding of what does it mean by 'art'.
It's the feeling that you get when you see a work of art (or anything! really.). Its about the connection, the artistic part of the object/image that speaks to your soul.

So it doesn't matter if its a painting, drawing, sculpture, photograph, video, furniture, music, architecture, cloth, natural objects, random objects…. anything. If you see something and it gives you a certain feelings, it's art to you. You are connected to it. You can feel it. It can be happiness, sadness, love, confused, excited, complex, mixed, amused, majestic, attractive, hatred, pain, memories, names, mystery, curiosity, questions, etc. It sparks something in you, ideas or memories, or just plainly feelings. 

And this comes to a personal understanding that your love ones, they are a work of art to you.

--

So, taking that as the basis of a work of art, i come to an understanding of why sometime artist can't really explain their works, or there's never really a specific idea or message in their works. Its just about how people/public receive or interact with the work, giving it a different meaning based on their understanding. It can be random images from the mind of the artist, but if it means something to certain people, if it gives a certain feeling to them, then it's art to them. Some might not 'feel' it, and theres nothing wrong with that, you can move on to the next piece and say "That is not art for ME."

So from here, you can never say "You don't understand art" to anyone. Or, "This is art, that is not". All you can say is "That feeling that you get when you see this, that is art."

This explain the kind of works that i never really understand, like once i saw this artist displaying an empty canvas, or the one with just a dot or a line on a large canvas. Its about how i feel about it, questions, emptiness, rage, anger, stress, confused, "wtf" feeling etc. That feeling is the art, not the physical artwork it self. and the more i think about it, it amazed me of how the simplest thing on a canvas could spark many feelings inside me.

And it's up to the artist to choose to explain (or not to explain) his works in his own word, even when they say "There's nothing much behind this piece, its just random beautiful images". You can't expect them to be intelligent all the time, having great ideas/messages hidden in their works every time. Great ideas comes from thousands of random things, hundreds of failures, tons of random scribbles or memories, and the question of "What if?". And the question of "What if?" brings us to a whole new world of random unexplainable imaginations that certain people might not understand and reject.

But if there's message in the work, that is a bonus.
And if the message is hidden, that is gold.

So the next time i see an artwork, feelings and attraction comes first, and then the explanation by the artist (if there's any) and then a complete understanding of the work.

As what people been saying, art is subjective.
And i think i just had a complete personal understanding of that.

note 1 : But this doesn't mean you can take the quality of your work easily. Always strive to be better, to be different, to give your best, in anything you do. If your work doesn't satisfy you, then experiment more. It takes time, but don't rush on it. Satisfy yourself first, before you bring your work out to satisfy everyone else. Don't try to be anyone else, be yourself, it will be reflected in your works. That is where your unique ideas and stroke comes from. Yes art is subjective, but i guess somehow everyone should at least strive to get it aesthetically great. Always remember that your artwork is a small representation of yourself. 

note 2 : This is a personal view.