I think I do recognise the feeling. There isn't really a big difference remembering something that happened a long time ago or from a dream. There is when you get a physical reminder (smells in particular seem to be a strong trigger). Both dreams and memories work in the same way from the perspective of your own subjective experience. Especially dreams have a very hard time making physical memories, since your body is in rest. But when you're awake and especially when you're aroused in some way, your body connects the memories to the physical sensations. In this sense your body is a memory bank and it stores your life. Your body grows, cleans, encapsulates, expulses, incorporates, so do the connections change or get lost in pure subjective memory.

It's this that can explain why old memories and dreams can feel so much alike.