According to Sean, he dropped out of MIT as an 18 year old Junior, and began traveling the country for five years with a backpack as his only possession. He stopped long enough to get involved on the ground floor with a Dot Com company and made a killing on his stock options before Dot Com's made their downfall. He lived in a 35 room Long Island Victorian mansion, filled with great art, furniture from around the world, and all the "toys." When he realized that he was living to maintain his possessions instead of enjoying his life, he left it all behind and took a job in Genoa City. At some point along the way he had a relationship with Phyllis Summers.
Sean arrived in Genoa City coincidentally to replace Phyllis Summers as Jabot Website Designer, complete with nose ring and laid back wardrobe. He lives in a high rise apartment with no furnishings but a card table, two chairs and a futon, in an attempt to return to a minimalist way of life from his younger years. But he does still keep a Picasso in the closet. Sean seems to have a lot of connections in his past, counting entertainers Lionel Ritchie and B.B. King among his friends.
The mysterious Sean seemed to have scoped out the options and chose "older woman" Jill Abbott as his companion. While Jill remained wary of this hot younger man and his motives, he managed to sweep her off her feet. Sean was a good influence on the embittered Jill, showing us a bit of the fun-loving innocent woman she once was. Sean moved in to the Chancellor Estate and lived with Jill. But Sean pressured her to get married, and Jill balked one too many times. Sean quit Jabot and returned to New York City.