Yeah my 10-month old son asks for me constantly(da da di da ta ti) if I'm away from him for more than a few hours. Separation is really tough for them to deal with because they don't have the tools or sophistication to understand why we're gone and that we're coming back. I had to spend a few weeks away from him when he was 4 months when my wife needed to be somewhere with a working kitchen and a clean floor and I needed to repair our kitchen and I think he was "colicky" during that time because he didn't understand where I was or when I would be back. This persisted during the week and then when I would spend the day with them he would calm down.