What kind of yarn did you use? I find that acrylics are generally more elastic than natural fibers, and if you wash and dry them they regain their shape. Something like Homespun (or as I call it homeshun) has no springiness at all.
Also, the type of stitch has a lot to do with elasticity. A ribbed pattern will be a lot more elastic than stockinette.
Steer clear of cotton or chenille for sure, though.