when is it wasteful vs wise?

Leftovers - the age old question - when is it being wasteful to throw them out vs when is it wise to throw them out?

I know many people who never eat leftovers - which, in my humble opinion is wasteful.  Then on the other hand there are times like I experienced today, in which Sharon pulled out a small container of onions, green peppers, mushrooms and garlic that had been fried up to put in omlets almost two weeks ago.  She looked at me and asked, "Do you think we should throw them out?". 

I'm not sure why, maybe it was because there was a time when I was younger that times were tough economically, but I HATE to throw away food.  It really bugs me.  Understanding my nature, I took the container, looked it over and not seeing any mold or fuzz, declared it perfectly good to eat.  I told her as long as we get it hot enough when we reheat it that it would ensure the killing off of any nasty stuff.  I then proceded to heat the concoction up in a frying pan, add a few eggs and cheese and Whaalaa...breakfast was served....

....not to terribly long after that Sharon expressed that she wasn't feeling the greatest and wondered outloud if it was the leftovers.  Pish Posh I replied.  They were fine.  Nothing to worry about.  A few minutes later Sharon was in the bathroom and I started to feel a tad "uneasy".  I reassured myself that I was experiencing some psychosomatic symptoms that nothing was actually wrong.  It was just the thought planted in my head by Sharon.  About 15 minutes later I too was in the bathroom.  Definately not psychosomatic. 

Why did she force me to use those darn leftovers!!

Thankfully the effects seem to have been short lived, but in the future I will be a little more cautious when it comes to the age of the leftovers I eat.