Tonight I did a Criterium race on my single bike. As I was warming up, it dawned on me, I hadn't ridden a single bike in 3 months. (Note to self, don't pull the bike off the rack the morning of a race when its been sitting unused for 3 months, without checking things a few days before)
Warming up just felt weird, and the bike felt overly twitchy. Went away in the first couple of laps, fortunately.
This season we've put 4500 miles on the tandem, and I've only put 2000 on my single bike. Going forward, I think I need to make a conscious effort to ride the single occassionally.