I have a cactus in my apartment. I kept him (it's a he, though he has hot pink flowers) by a window that didn't get any sun, a window that was open all the time. So a small chunk of him died, and I had to cut off all the wilted, shriveled limbs. It was weird. So I went into super-mommy mode, guilty because I almost killed the only living thing I own, and moved him to my bedroom window where the sun shines through all day long. When I open the window at night, he sits on the floor. In the morning, he stays on the sill in the sun. I also bought some cactus food to help him rejuvinate. Did you know it's actually called cactus JUICE?
I don't know why I like cacti so much.
photo via mossière