My little boy has just turned 15 months and used to be really lively, talkative and sociable. Just recently he seems quite sad and subdued and wants to play on his own all the time. He has become very shy and everytime a stranger approaches he buries in my shoulder. He is my first baby and I am just wondering is it normal to for a baby to do a complete u-turn on personality or is there something that could be bothering him? I am just worried that he seems so sad and doesnt interact at all with people. I dont think he is ill as he is still active. He just doesnt seem to chat and smile like other babies do. Am I being a typical over worried first time mother or is there something I can do? There have been no major changes in his life so I dont think that could have affected anything. Any advice would be appreciated!