I don't know if I'm the worst person for this question or...depending on one's money-attitude....the BEST person to answer this!!
I am a very frugal-minded woman....always have been. Some of the "waste" I witness makes me cringe.
Lavish vacations that individuals know they simply cannot afford.....and will be "charging" everything and paying for it (10 times over it's value) for years.
Paying FULL price for any major purchase for lack of shopping around to look for discounts and bargains.....and doing no research on the product
Luxury vehicles strictly for "appearance/status ruse" when a vehicle at half the cost will do quite nicely.
buying every toy, gadget or current craze-item on the market, not knowing if you will even get a benefit from it
Lots of other things...but I think this may be enough at the moment.!!