The same for me. Once I worked out why I wouldn't be able to see them I spent a lot of time bluffing other people into saying that they saw more things than they really did. I invented details, the idea of double stereograms, pictures which changed dramatically when viewed upside down or across a different plane and my favourite, the oscilostereogram which changed when tilted (like those leaping tiger action pictures).
The same for me. Once I worked out why I wouldn't be able to see them I spent a lot of time bluffing other people into saying that they saw more things than they really did. I invented details, the idea of double stereograms, pictures which changed dramatically when viewed upside down or across a different plane and my favourite, the oscilostereogram which changed when tilted (like those leaping tiger action pictures).