I had a dream of my dad soon after he died (just before I was 5), and for years afterwards I was convinced that his spirit had somehow communicated to me through that dream. But I wanted that to be the case, and that definitely skewed my interpretation. Nowadays I'm not even sure that I had the dream. It seems quite conceivable that it was a false memory.
I had the same experience. In fact I had a series of dreams where he seemed to be learning something and then a last one where he said goodby. Seemed more me coming to terms with his death than anything supernatural.