...it is slang. slang for "that's unfortunate". I went to put on my shades but remembered that I forgot them.. "that's a bummer."
However some people can be what one might call a buzz kill or a Debbie downer and that person would be a perpetual bummer and might necessitate hitting the ignore button.
Its all situational. Like a down day on a stock.. lol. I didn't buy another 5k on the dip and now its up 100%. That's a bummer for sure.
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