mental accounting
n.— «Experts say, for example, that such people don’t fall prey to something called “mental accounting,” in which an individual creates imaginary boundaries between different “types” of money.…People who treat money originating from varying sources differently do so at their peril: “If you won £100 at the horses, you’re likely to blow it on champagne, but if you found £100 in a savings account, you might just leave it there.”» —“Think about it: you can sort out your debts” by Helen Monks Observer (United Kingdom) Dec. 30, 2007. (source: Double-Tongued Dictionary)
Further reading
In 1916, a small-town newspaper in Pennsylvania printed a fanciful item about a local gathering with a guest list that included, among others, Miss Ella Vader, Mr. Ray Zor, and other punny names. This is part of a complete episode. Transcript of...
The expression to turn on a dime means “to change quickly.” Early on the phrase referred to horses or horse-drawn vehicles and later to motorized ones, and suggested the idea of changing direction quickly and easily without needing a large turning...