This friendship could be characterized by a lot of comfort and warmth, but these seemingly positive signs will also have a challenging effect. Your friend may be warming to something in your past that no longer has much to do with who you are or where you're going. It may feel comfortable to spend so much time talking about the past, but what you really need is to move forward in life.
It's also likely that you're responding to something within your friend that reminds you of your past: Perhaps the way they show you affection is familiar to you, or their sense of values and creativity reminds you of someone who used to be important in your life. Take a close, honest look at your connection to determine if you're more interested in each other for these old, outmoded reasons than anything future-oriented.