An elderly cat keeps turning up at his neighbor's door for the simple reason that he no longer knows where his own home is.

The sad-looking kitty can be seen in a post shared on Reddit.

"Neighbor's cat has alzheimers, forgets that he doesn't live here," reads the caption.

Since the cat has been suffering from the disease, he has been a regular guest at his neighbor's house.

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The poster told Reddit users not to worry, though, assuring them "i know his parents and he always gets home safe."

His post was well received and sparked a broad discussion about animal health.

"I couldn't help myself, he'd be my cat now...." wrote one user in the Reddit post's comments. "He lives wherever he damn well pleases," joked another.

"i think you might have memory issues he does live there poor guy let bro in," said a third.

Cats can indeed become senile and suffer from forms of dementia, get confused and lose their bearings, and even forget where their litter box is.

If this is the case, don't scold your cat – have some patience and compassion for the little ones as they navigate their new normal.