salt away

'make it stick' (三人の共著)を読んでいます。 'Embrace Difficulties' の章から引用します。

Much of how we run out day-to-day lives is guided by the ephemera that clutter our short-term memory and are, fortunately, soon forgotten--how to jigger the broken latch on the locker you used when you suite up at the gym today; remembering to stop for an oil change after your workout. But the experiences and learning that we want to salt away for the future must be made stronger and more durable--in Mia's case, the distinctive moves that will enable her to hit the ground without breaking an ankle, or worse.

"salt away" の意味を調べます。

・Collins Dictionary: If someone salts away sums of money, they save the money for the future, often illegally.: The president was accused of salting away millions of dollars in foreign accounts.
・Wiktionary: To save or preserve (especially money) for future use.: You have more than two thousand salted away, I know, Moses, between prize-money, wages, adventures, and other matters.
・The American Heritage Dictionary of Idioms: Also, salt down. Keep in reserve, store, save, as in He salted away most of his earnings in a bank account. This idiom alludes to using salt as a food preservative.