I'm not trying to fool you! While octopuses do in fact have eight appendages, recent studies  show that several of those – six to be exact – function more like arms with the remaining two acting as legs to propel them through the water. One of these researchers, Alex Gerard, curator of the Sea Life center in Brighton, England explains it like this:
Their front two tentacles will be used for a lot of exploratory work and then the ones immediately behind them will then be used also if further investigation is needed. Then the further back you go, the more the limbs are used for propulsion and movement. From what we've seen, all the limbs basically have the same capabilities. But they seem to favor this system and it works well for them. They have that facility, unlike humans where if we tried to grab our food with our feet we might fail miserably.
So, I guess it's more a technicality but I didn't know octopuses could do things like a Rubix cube or even twist open a jar as seen here – guess you learn something new every day!