You are right, to be a successful investor you have the characteristic of keeping patience, and not getting played by the market sentiments, the ones who claim themselves as investors or long-term holders, they should not see the news regularly, although it's not a good practice to not see, but if you keep seeing the news and the current situation of the market. Then a time will come when you will feel like exiting the market and you will think of entering again when the price will dump.
But you will end up losing it all, so considering this fact, it won't be wrong to say, we should not keep a keen eye on the market situation when we are making investments, like for the long term. Long-term means we don't care if the price goes up or down for like 2 to 5 years. The time period can depend on the individual mindset.