Makeup Prompt - Write about what you used to know how to do

I used to know how to play chess at a fairly advanced level, understanding everything from basic opening principles to more intricate endgame techniques. I could visualize moves and anticipate my opponent's strategies, thinking several moves ahead. I was familiar with popular openings like the Sicilian Defense, Queen’s Gambit, and Ruy Lopez, as well as different tactical motifs such as forks, pins, and skewers. Endgames, like king and pawn versus king, or checkmating with a king and queen against a lone king, were also within my grasp. The nuances of positional play, like controlling key squares, pawn structure, and piece activity, were areas I used to analyze carefully to maintain an advantage.