On Magnus - there's a huge chess subculture, so it's hard to reference any given thing. I might start with this [1]. He's giving every single reason for why he might decline in the future, which I think terrifies him. It's quite unpleasant to imagine that you'll not only never be as strong as you once were, but that you will start to see your strength all so gradually decline, year by year.
So amongst his million preemptive excuses, you also him somewhat rewriting history now claiming his "2 down, 5 to go" comment was "just trolling." He made that comment after his second world championship victory, which was extremely convincing - as it was against the previous generation of players. For some context, no chess world champion has ever won/defended their title more than 6 times. The most dominant champions ever, Lasker/Karpov/Kasparov all won/defended 6 times a piece. Magnus, it seems, will go down with 5.
[1] - https://www.chess.com/news/view/carlsen-on-his-future-person...
Re: petere, it's not about Romans, rather the original meaning that provides insight into the pure form of competition. There is a great book called "True Competition" by David Shields that explores this topic and tries to answer the question "How to make competitions more healthy so they don't deteriorate into something that destroys the original spirit of competition".
It's also interesting that in English word "competition" is also used for business, economics, biology, and political sciences. In business, it's clear that competition is a tool to incentivize market players to pursue the highest quality of service at the lowest cost ("show your best"). Again, in monopoly/monopsony, there is no competition – we need other players for that – and no incentive to "show your best".