In is our gain also our loss what is most likely the reason that the authors father becomes excited when he sees his daughter eating cereal

- It reminds him of an old commercial that he once enjoyed.

Explanation:

In the context of "Is Our Gain Also Our Loss?' the most probable reason that makes the author's father delighted when he observes his daughter having cereal is that 'it recollects his memories of an old cereal advertisement that he really enjoyed watching.' This gives him a nostalgic feel and he's down the memory lane when he was a young boy which makes him overjoyed and elevated at the same time. Similarly, when grandma sees her childhood photographs, she too gets emotional and reminiscent of her old days.

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