Here is a "silly frugality" for those who are still working. And somewhat related to leftovers...
Megacorp used to reimburse you for actual daily costs when traveling. Of course, you had to turn in receipts to provide it. And then someone had to process your expenses, verify the receipts, call you with questions, receipts would get lost, etc.
So... Megacorp decided no more having to turn in receipts, as the cost of processing expenses reports was (in some decision makers mind) too expensive. Based on their analysis of years of travel expenditures, you get a set allowance per day. If you exceed it, tough luck. If you come in under it, fine, Megacorp does not care, you keep the balance, no questions asked. So you you just put down the number of travel days and you get the allowance amount automatically reimbursed.
So... the "silly frugality" is to see how much of that allowance one can hang onto. It usually boils down to where are the cheapest and healthiest places one can find to eat. Mickey D's 5/6 nights in a row will not cut it.
An informal network of folks has developed who share good but cheap places to eat at various travel locations (we call them "price performers"
). Some to adhere to this as much as possible. Some think "why bother", and see the per diem as helping to subsidize their big fancy meal. Guess which group is more likely to reach FI/RE...
It gets really "silly" when the travel event is a conferences. Some of these conferences will have informal evening "networking" session where appetizers are served. Sometimes these are really, really good appetizers... and the "silly frugalers" see if they can make a meal of it to avoid having to buy dinner somewhere else that night. If one is staying in a hotel where the room has a fridge and microwave, the "extreme silly frugalers" will try to figure out a way to bring some of the food back, and have it as leftovers for some of their meals the rest of the week.