My dear departed puss was definitely on a higher plane when it came to intelligence. He used to:
Puncture pouches with a claw and suck all the gravy out. Of course this let the air in, so the remaining meat would become rancid, but that didn't matter to him as he knew his trusty slave would just buy more.
Help "undesirable" men (to him, any male was a rival) out of the front door with a bat of the ankles and follow them out to the stairs with an indignant miaow to hurry them along.
Knock on the front door to be let in (no cat flap as was in rented). He also used to poo in the neighbours' cats' litter trays, thus leaving his fragrant.
If he thought he was being filmed he'd run into his crate and close the door behind him.
When DD was tiny she had an abacus. DCat would move the counters across and back again, like he was doing sums.
He would also wait outside the bedroom until we'd, ahem, finished, then run in with an indignant miaow and wedge himself between me and DP, usually with his back paws in DP's mouth. He did once try and interrupt by climbing on someone's (pre DP) back and holding on with his claws, but must have been put off by the reaction so since then always reluctantly waited.