I’m inclined to believe it. I worked for a Wall Street firm when the stock market switched from fractional quotations to decimal. Lots of my coworkers printed out a conversion table from fractions to decimals, and even so often had problems figuring out which of two quotations was greater than the other one (in decimals). Those were smart people, but if you work with one system for so long, your brain gets hardwired and difficult to change.