Fitness question (hence the category choice)?

So I keep seeing all these things about "rock hard" abs and having a "hard" stomach and all of that BS. I've never been much into fitness so I personally wouldn't care, it's just that, unflexed, my abdomen is REALLY squishy. Like I don't feel any muscle there when I press on it unless I flex the muscle. It just feels like a layer of skin.

I haven't worked out for a bit so maybe that has something to do with it.

My BMI is normal

Any reason my stomach would be squishy?
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Fitness question (hence the category choice)?
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