... is that once you accept someone or something as competition you've already lost.
You'll always be busy observing their moves.
Trying to figure out what they could be doing next.
What their next move is going to look like.
And what you could be doing to be able keep up or to defend your position.
And the moment you do that you've already lost.
Because you'll lose your only competitive advantage.
The advantage of only competing with yourself...
[Related: I stopped giving a shit a long time ago]