Clyde is a bit retarded. On one hand, he can't seem to learn any of the commands we try to teach him, and he is constantly yowling and running around. But Clyde is quite clever when it suits his needs. Today he finally mastered the skill he's been working on for a while now, specifically he's learned how to open doors. In our house we have lever door handles, which makes this much easier. He also can only open doors that he can push open, but he's learned to do it, and it's a little bit disturbing.
To test this, I just put him upstairs, outside the basement, and then shut him out. He scrabbled at the door for a while, then after about 30 seconds, he got it open, and nonchalantly strolled down and climbed up on the couch. He's a strange little beast that Clyde.