One of my cats Phoebe goes absolutely crazy every time anyone walks into the kitchen. And you definately can't open the fridge without her cute little nose poking in! She persists in jumping up on the kitchen work surfaces whenever I am preparing food much to my annoyance! But she will never learn. It's almost like she doesn't have that shut off function in her brain - she never stops eating, bit like a pig!
Our other cat Vinnie does cry out for food and get all balshy, but only really for his own cat food. Two different cats!
My mum and dad's cats do not beg at all, and one of them doesn't even seem that interested in her cat food - perhaps she eats too many mice in the night!
Anyways, I don't think it's strange, cats are very complicated beings all very different in personality and can suddenly change their pattern of behaviour for no particular reason - just enjoy their silly little ways! :-)