I find it interesting that nobody has mentioned the Muse yet...
According to greek mythology, the Muses were 9 goddesses those task it was to incite creativity and inspiration in individuals.
Wilkipedia can explain it better than I ever could:
In Greek mythology, the Muses (Greek Μοῦσαι, Mousai: perhaps from the Proto-Indo-European root *men- "think") are a sisterhood of goddesses or spirits, their number set at nine by Classical times, who embody the arts and inspire the creation process with their graces through remembered and improvised song and stage, writing, traditional music and dance. They were water nymphs, associated with the springs of Helicon and with Pieris, from which they are sometimes called the Pierides. The Olympian system set Apollo as their leader, Apollon Mousagetes. Not only are the Muses explicitly used in modern English to refer to an inspiration, as when one cites his/her own artistic muse, but they are also implicit in the words "amuse" or "musing upon".
According to Hesiod's Theogony (seventh century BC), they are the daughters of Zeus, king of the gods, and Mnemosyne, goddess of memory. For Alcman and Mimnermus, they were even more primordial, springing from Uranus and Gaia. Pausanias records a tradition of two generations of Muses; the first being daughters of Uranus and Gaia, the second of Zeus and Mnemosyne. Another, rarer genealogy is that they are daughters of Harmonia (the daughter of Aphrodite and Ares) which contradicts the myth in which they were dancing at the wedding of Harmonia and Cadmus.
One theory I have is that we are all born with all the ideas, thoughts and inventions we will ever think of already locked away in our mind, and as we go through life certain events, sights, sounds or scents will unlock one of these ideas. I think that's why certain sounds or smells etc seem to remind us of something we sometimes can't quite put our finger on...
