Best before dates are sometimes crazy. I've seen sugar and salt with best before dates. They're preservatives! They do not go bad...
I'll look at the dates to have a general idea when I should be looking/smelling/tasting more carefully but I'll still make my judgement based on my senses, with the exception of meat and fish. Thing is, everything fresh that goes into the freezer doesn't have a "Best by" date anymore. Usually I'll write down when I stored it in the freezer since I buy a large packaging and divide it at home.
@jellysundae For larger blocks of cheese I do the same, cut of the mouldy part and continue. With grinded or sliced cheese that's not really possible though so I'll throw that away if it's moulded. I just really dislike throwing away food with so many people on earth starving.