Discouraged after investing after everyone said "don't time the market" yet I see multiple threads with people exiting their positions

After holding cash for a crash and being on the sidelines for too long, I decided to follow the advice of everyone saying "time in the market beats timing the market" and invested 2 weeks ago into the SP500.

Now that I'm finally in the market I see lots of posts with people saying they're exiting their positions or that now's not a good time to invest.

I'm so confused and also discouraged that I'm not sure what to make out of this. Why are people selling if you're not supposed to time the market?