who seeks power above all else?
people who have a void to fill. Having never felt love or a true sense of family - the only thing that would have helped Voldemort define himself would be being 'good' at something. being able to have 'power' over something or someone.

he may not have recognised it was lack of 'love, humanity and nurturing' - the power hungry rarely recognise this 'lack' in themselves. but I think this lack of 'belonging' - until he got to Hogwarts.... was the single formative idea that drove him to be the best, most glorious, most feared, most powerful, most famous wizard of all time (atleast in his own mind)