Since you can write that question, you cannot possibly have a smooth brain. Please totally disregard whoever said that about you.
Urban dictionary - smooth brain - a term of abuse - A stupid person; it refers to the lack of surface area on an individual's brain. The general thought is that the more surface area (wrinkles, creases, etc.) a brain has, the smarter the person is. Conversely, a person with a smooth brain (no wrinkles) has less surface area and would, therefore, be stupid.
"Lissencephaly, which literally means "smooth brain," is a rare, gene-linked brain malformation characterized by the absence of normal convolutions (folds) in the cerebral cortex and an abnormally small head (microcephaly). In the usual condition of lissencephaly, children usually have a normal sized head at birth. In children with reduced head size at birth, the condition microlissencephaly is typically diagnosed. Lissencephaly is caused by defective neuronal migration during embryonic development, the process in which nerve cells move from their place of origin to their permanent location within the cerebral cortex grey matter. Symptoms of the disorder may include unusual facial appearance, difficulty swallowing, failure to thrive, muscle spasms, seizures, and severe psychomotor retardation.
"There is no cure for lissencephaly, but children can show progress in their development over time. Supportive care may be needed to help with comfort, feeding, and nursing needs. Seizures may be particularly problematic but anticonvulsant medications can help. Progressive hydrocephalus (an excessive accumulation of cerebrospinal fluid in the brain) is very rare, seen only in the subtype of Walker-Warburg syndrome, but may require shunting. If feeding becomes difficult, a gastrostomy tube may be considered."