This sounds weird, but I'm not lying just to prove a point here - last winter, I busted out the rollers a lot just to get my technique back after training nearly all winter on a trainer. Didn't take too long to get back my roller proficiency including drops, sprints, no-look, no handed.

Hit the road on a nice group ride in March, and wow, I was terrible at bike handling on the roads for that first ride. The rollers had gotten me so used to riding in a stock-upright position that I felt totally unstable even on a very safe lean into turns. I was hammering the climbs, but I was perhaps the slowest one on the descents that day. Fortunately, by the next ride it had vastly improved, and after 3 rides I was essentially back to normal, but it was quite surprising to see how all that roller riding make me really scared of allowing even a slight tilt on the bike (since you'd go off the side on the rollers.)

This obviously wouldn't have been a problem had I done rollers and maintained regular outdoor riding.