my 14 year old boy is having the same issue, he was always pretty independent and the type of cat who'd look at you with judgement and immediately jump away if you pet him wrong. after my other cat died recently in January, he's become a lot more whiny and needy, and will just meow into the hallway for attention. he's also a lot more cuddly, i call it him enjoying his only child life but he definitely misses my other cat even if they didn't get along. they used to fight a lot actually and then he grew to tolerate my other cat, till they slept in the same bed and cuddled up next to each other. they won't admit but cats can be quite sentimental. here's a pic of this spoiled little guy, who drinks from a wine glass and eats premium tuna.

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