Cat
Cats have dominated human cultural output since the ancient Egyptians had the questionable judgement to declare them divine beings. This was humanity's first major social media mistake, and cats have been exploiting it ever since. The internet, that vast repository of human knowledge, is approximately 74% cat content by volume.
From Garfield to Grumpy Cat, from keyboard cat to the inexplicable phenomenon of cats wearing tiny hats, the feline has colonised our collective consciousness with the same quiet efficiency it uses to colonise the one spot on the sofa you wanted to sit on.
Skateboard
The skateboard emerged in 1950s California when surfers, deprived of waves, decided to recreate the experience of falling off things on dry land. It subsequently spawned an entire counter-culture movement, complete with its own fashion, music, and distinctive vocabulary consisting primarily of words like gnarly, rad, and ouch.
From Tony Hawk to the X Games, the skateboard has achieved legitimate sporting recognition whilst maintaining its outsider credibility. This is the cultural equivalent of being invited to the establishment dinner party and still managing to look cool.
VERDICT
The skateboard's cultural impact, whilst considerable, spans merely seven decades. The cat has been shaping human civilisation for millennia. When archaeologists discover ancient Egyptian tombs, they find cat statues. When they discover 1990s time capsules, they find cat memes. The pattern is inescapable.