Suppose we have disposable income that would buy one of the following items, which cost roughly the same amount:
1. An iPad.
2. A Dell tablet/notebook combo (or other computer).
3. Dental appointments for the family.
4. A vasectomy.
5. Repairs for the Mazda.
6. A few days away for vacation.
7. A flat-screen plasma TV (to replace our 1998 old-school box).*
8. Save the money for probable unbudgeted expenses in the coming year.
I go over this list in my head trying to rank order them. The "wants" and the utility they bring are vividly clear, but acquiring them would bring some negative utility in the form of guilt over not purchasing a "need." There is a time-consistency problem here as well.
Kids, this is how you know you've gotten old.
*A toddler visited our house recently and couldn't find the TV. He didn't recognize the box we had as being a TV. (Similar to how Elias doesn't understand that our television doesn't operate as a touch-screen like the iPod does.)