If it helps ladies, some kittens are very playful and then suddenly, one day, they just become all grown up and just stop doing playful things. They turn into staid old cats and do the sleeping, eating thing until they are old codgers. It doesn't always point to them having had a rough life and no longer wanting to play or being able to.
When Oscar was a kitten he was really full of beans. The flat I lived in had a load of picture hooks in the hallway and we hung some old baseball caps on them. This was fine until we replaced our bed mattress and the old one was propped against the wall - under the baseball caps - until we could get rid of it.
Well, a certain little ginger kitten thought this mattress was his own personal playground and used to go mental on it. His favourite trick was knocking the baseball caps down.

He was a right little bundle of mischief.
But when he was about 2.5 - 3yrs, this fun all stopped and he became a serious wee man!!! He's now 14.5yrs old but he's been that age for over 11yrs. He's been a pampered puss all his life so there was no reason for him not playing except that he didn't want to.
I hope this makes you both feel a bit better and less sad. Maybe your kitties did have their fun but had 'grown up' by the time you got them
This picture is from one day when the baseball caps moved faster than Oscar could. :lol:
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