I think if you continue with a routine he will adjust. When we say it's time to go to bed, Rosie jumps up and gets in the bed. She knows because this is the routine since she was 6 months old. We always say the same thing too. I think that helps as well. Mikki has to be put in the bed but she goes under the covers and lays down. Once she is down, she doesn't move until I do.
