Not really. It just means you have made a inaccurate calculation. When it comes to money I thought "seasoned investors" liked accuracy. Or am I wrong ❓At 63 you'll do 60 in your head and know that the item is going to be cheaper than your 60 calculation. Then you know you have a bargain.
In this day and age who does not have a computer in their pocket that can do the calculations for you...