What does it mean when you keep dreaming of my son and he is always 7-8 years old. He is in his mid twenties now?

In the mind of a parent, children tend always to be children, regardless of their actual age. So it is not at all unusual for grown offspring to appear in dreams as small kids. The dream expresses the dreamer's own feelings, which might be just as caring and protective of a 20-something now as they were of that 8 year-old two decades ago. Consider the son's present situation and whether you long to offer help or protection to him. Alternatively, the child in the dream could represent someone (or something) else the dreamer cares for and longs to protect. Yet again, the dream child could be a symbol of the dreamer's OWN childhood self, and the need to express something in a childlike way, perhaps with abandon and unselfconscious delight.