In the series Beyond is his personal hallucinations, delusions and dreams are central. Many of these experiences were gained by Sander during a long-term hospital stay. In fact, at the age of twenty, Sander went through his second heart operation, during which he was hospitalized for a month. During his hospitalization, Sander was frequently under sleep medications, which lead to many hallucinations, delusions and dream images. With the series Beyond, Sander incorporated many of these personal experiences. This shows where his personal symbolism comes from and shows the basis and source of inspiration for many of his works.