Basic requirements for ex-spousal dating exploration include a significant duration between divorce and dating, a strong belief in change, and considerable courage to go back into a potentially stressful relationship with "old baggage" that may trigger unresolved bad feelings, no matter how good one's intentions.
Between divorce and deciding to date, a highly important personal development needs to occur, what psychologists call "separation and individuation".
My advice, however, is to not assume anything about your new/old partner, but to relearn about this person.
In your time apart, your ex could have done a multitude of really cool things, like contemplating a new career path, getting really into meditation or become the biggest Chicago Bulls fan in the world.
This maturational process resembles what children go through as they separate from their parents and take responsibility for their lives.