My daughter made the transition from bassinet to crib to bed smoothly, but with my son it's been a different story. He did fine in the cradle, but has scarcely slept through a full night in his crib. I don't know if it's the sound of the side sliding up or the fact that he's surrounded by bars that never sat well with him. But the minute he lays in a bed, he's sound asleep (even smiling) in a matter of minutes.
So now that he's 18-months, we're taking down his crib and trading it in for a big boy bed. Like my daughter, many tots make that transition around two. When did your lil one make the move?