"Chess is like life." Really? Howso?

I hear this sentiment uttered on occasion, although I fail to see how this particular two-player board game has any relevance beyond.. well, the game and its players.

Folks can learn it, play it, practice it, get better, which can broadly apply to many things: sports, musical instruments, so-on. But as far as the specific skillset required by biological beings to excel at chess (visualization, tactics, strategy, etc.), these aptitudes may carry over into other aspects of life to an extent, but the analogy ceases there.

There are of course the individual pieces and pawns which can be imagined symbolizing various roles in society or what have-not, but that is really a stretch. In a literal sense each piece represented some role from Dark Age kingdoms, but those times are millennia passed.

Who here actually believes in this metaphor, and in what ways?

Willy, did you know that you can actually write all your ideas in only one message?

"You tend to be blocked by your own pawns"

'pawns' being a metaphor for something?

"You are your worst enemy"

While there are instances in life where this holds true, this ideation is not broadly true, let alone even applicable to chess.

"It has ups and downs."

Meh, half-true.  If implying to respect of a round, only on the surface.  with respect to wins and losses, okay.. but so what?

"You never kno what you're going to get." (grammar-corrected)

Not true, in either life or chess.  You might be caught by surprise, but you learn from that and not an 'always\never' type of deal.

Many things are black and white actually. 

I hope you are not one of those people who think absolutely everything is relative and there is no absolute truth in anything, and that 2 plus 2 can be monkey. 

"Even on the brink of success, one overlooked detail could be your downfall."

Can you provide a couple of real-life facets to which this statement applies?

That is one example shy of two, with respect to only chess and not any other aspects of 'life'.