The nose knows people! Just smell and look, I have eaten many past due things and scooped of layers of fungi. I have never been ill from it, 34 years and counting.
Sure, be careful with chicken and turkey but yoghurt for example, come on, it's basically a bottle of bacteria already and the smell is hard to ignore when it actually goes bad.
I generally agree, but be careful with moldy food. Some mold species produce mycotoxins that can be quite dangerous (e.g. aflatoxin can induce liver cancer, some mycotoxins can't be degraded and build up in the liver).
Simply removing the fungi is not enough, since the toxins diffuse into the food matrix (e.g in jam, yoghurt). An exception is mold on fruits and vegetables, there you can cut out the affected areas, the toxins can't diffuse across the cell walls.
> I have eaten many past due things and scooped of layers of fungi. I have never been ill from it, 34 years and counting.
Nobody should follow this advice. Most people will instinctively recoil from what you describe, for very good survival reasons.
The fluffy stuff on top is just the surface part of the fungus, its main body actually lies inside the food. The reason why you've never been ill from it is probably because your body is used to this. However, there can easily be long term (and sudden short term) health consequences from ingesting fungus toxins - including persistent infection, cancers, and neurotoxicity.
Sure, be careful with chicken and turkey but yoghurt for example, come on, it's basically a bottle of bacteria already and the smell is hard to ignore when it actually goes bad.