Riding my bicycle the other day, I thought "having learned how to ride a bicycle in the past, for me the experience of riding a bicycle is just like riding a bicycle." And then I thought, what did we say before bicycles to capture the concept of a difficult skill that is (nearly) impossible to forget once mastered? While there are phrases like second nature that might capture this, I'm specifically looking for a simile.
From some light research I've done, I haven't found any definitive answer to this question. I have tried to think what would people before the invention of the bicycle use as an equivalent and, because the bicycle was one of the first wheeled transports, I believe that the only thing that can be compared is the horse.
Horse riding is not an easy skill, but it's not easy to forget once you learn how to do it. It's almost like riding a bicycle. According to the wikipedia article on the history of the bicycle, the term bicycle was coined in France in the 1860s". Any similar simile should have existed before the word bicycle even existed.
I did an Ngram search on the hypothetical term 'like riding a horse' compared to 'like riding a bicycle' that brought the following results:
Also, according to Google Books, the first printed example of the idiom was in 1917 and then also observed in 1933:
November 1917, Boys’ Life, pg. 6, col. 2: “It’s like riding a bicycle,” Ritter argued. “You never forget.”
7 May 1933, Springfield (MA) Sunday Union and Republican, “Trouble with Roller Skates Is They Roll” by Weare Holbrook, pg. 5E, col. 7: “They say it’s like riding a bicycle,” I muttered encouragingly. “Once you learn how, you never forget it.”
I'm not sure if this answers the question, but I'm very curious to know if there really was a similar idiom before the invention of the bicycle.