Both at home and at work, I have two monitors, but I keep the second one off maybe 75% of the time since I'm doing things that don't require the additional screen real estate and I don't want to get distracted. It's still totally worth having it available for the 25% of the time when I'm doing tasks that really require it, though.

(At work I really only need to see one window most of the time. At home I do more stuff that requires multiple windows, but I use a tiling window manager which helps get the most out of the first monitor before needing to add the second one into the equation.)