I went through a period where I played darts, quasi-competitively in my mid-30s. As an aside, Paul R. is the person I credit with introducing me to darts. For the duration of our companionship in Atlanta, he never once let his poor, competitive girlfriend win. What a gift. It is a beautiful game, with lots of opportunities to learn.
In any case, there was a player here, in Los Angeles, who could reliably throw off my game. He was a large, squat, angry sort of man - the kind you weren't surprised to find was unhappily divorced and also racist. He would walk up to the board and chuck his darts, unceremoniously, one after the other, thunk thunk thunk, in quick succession. He seemed not to care where they hit, but they did more often than not.
At some point I noticed when playing him I spent less time finding my footing, less time aiming, and was hurrying my throw (thunk thunk thunk). I was unconsciously imitating this man's rhythm and his attitude as well - and it wasn't working for me. I only began playing better against him when I reclaimed my own personal rhythm and took my time aiming again, but it took work.