(A prompt I had to answer in 8th grade art class.)
To be inside of a lemon would smell good, be hard to move, and dark.
First, it would probably smell good to be inside a lemon. Normally, air fresheners are made to smell like fruits, sometimes lemons, so it would smell good, until, of course, the lemon gets rotten.
Second, it would be hard to move around. How would you get inside it? And if you did, you'd have to make a hollow area for yourself. Then, when you start moving around you'll squeeze juice into your eye, and that would hurt.
Finally, it would be dark. If you were inside a lemon, you'd be closed in without any light.
So, if you somehow managed to get yourself inside a lemon, it would smell good, be hard to move around, and it would be dark.