Playing chess at a reasonable level has many facets that non-players might struggle to undestand (like any skill perhaps).

Before you get to that level, there are the fundamentals, which themselves are quite difficult; knowing the pieces and their moves and value, having awareness of the whole board so that if one of your pieces can be taken, you prevent it. Later more complicated "future" awareness develops so that tactical tricks can be avoided. After this, most players have a little plateau because you have the tools to play but how do you go about getting that end result: checkmate. Perhaps a few basic attacks were learnt in developing the basic skills but mostly these are futile against players who are beyond the basics.

So then, ideas of strategy come into it, how to start the game (opening, a chess players' serve) , techniques nearer the end of the game when pieces are few (endgame) are slowly absorbed so that the game starts to have structure and almost a sense of predictability.

Most of the above is knowledge-based. Then comes where the brain-power is really required. Calculation into the future is a skill that takes a long time to master. You need to organise your thoughts into a logical order, then use your imagination to move the pieces on the board in your head.

Watching a good chess could be more engaging than looking at art (Xin will argue of course). Art tends to have one surface to admire and maybe some context or meaning embedded there. Just like a classical music symphony, there are themes on the surface and maybe a setting or feeling that it wishes to invoke.
Chess, however, has invisible symphonies, and implicit ideas in every frame. Every move the chess player makes is just one of the many choices that were analysed, with multiple responses and possible counter-responses and so on and so forth. Each position has so many potentialities, only one of which is lived out, but all of the arrays of variations and possible lines contain drama, complexity, unbridled aggression and staunch, creative resolute defence.

When I was at the peak of my chess interest, I could stare at a position for days and find new ideas and complicated lines. I have done that again recently too. One such position I found so many interesting aspects that I was compelled to write them all down (in chess notation). I still missed the best line! (which was pointed out by my friend Paul). Again recently I have been playing another chess friend Aaron. One game, although a little dry at first livened up into a double-edged struggle, with the advantage see-sawing between white and black. The end position could have been forefully drawn by either white or black (boths sides could "perpetual check" or check the other king for enternity which is decided as a draw) but also both of us had a chance to win or lose. I didn't like my chances so sacrificed a rook to force the perpetual check.

Despite it being error-ridden (he should have won and perhaps so should have I), it was a delightful game with a lot of hidden variations.

That is the joy of chess.