With plenty of nurturing, love and attention, your baby's mind will develop normally. Provide him an environment in which he can explore as he gets older. When my daughter was that young I would read to her, sing to her, listen to music and dance with her in my arms. I made it a point to talk to her normally and she seemed to pick up on language quite quickly.
When you are with your son simple point out the colors of the things around him, provide different textures and colors he can explore, talk to him as if he understands everything.
As others have said, I've seen a lot of moms in the grocery store with their baby. Some just do their shopping without addressing their baby. Others are completely engaged with their child as they shop. They talk about the different vegetables, fruits, talk about what they are seeing, how it feels in the store (cold or warm), etc. They also talk about what they are doing, what they will do next, what they are having for dinner, etc. Keeping your baby engaged is a good thing and never forget their are right there, ready to soak up their environment just like sponges, even when they are tiny.
Most of all, give him lots and lots of love.