I don't agree that therapy is the only situation where you're not "allowed" to date someone who could be the love of your life. I think dating the partner or spouse of a sibling or other family member is off limits. The same goes for a very dear friend. Therapy is an unusual relationship and doesn't mimic any relationship in real life. People will do what they want and if that means getting involved with your therapist, so be it and hope for the best. I think the point is there are many times in life when you may come across "the one" but for one reason or another the stars don't align and a relationship isn't feasible. It's not an antiquated rule - it's one that has gotten stricter over the years to address abuses that have come into public eye.