Jared Spool talks about what makes a design seem intuitive:

In our research, we've discovered that there are two conditions where users will tell you an interface seems 'intuitive' to them. It only takes meeting one of the two conditions to get the user to tell you the design is intuitive. When neither condition is met, the same user will likely complain that the interface feels 'unintuitive.'

Condition #1:
Both the current knowledge point and the target knowledge point are identical. When the user walks up to the design, they know everything they need to operate it and complete their objective.

Condition #2:
The current knowledge point and the target knowledge point are separate, but the user is completely unaware the design is helping them bridge the gap. The user is being trained, but in a way that seems natural.

...via elearningpost