Your Opinion Matter and Can Help so Please Help!?

I just need someone else's point of view on this. I haven't heard from someone of my past...someone I dated for years. We stopped talking because after breaking up the person met someone else so the person decided to stop talking to me and I did the same and moved on. Now, after many years out of the blue I got a friendly message from the person wishing me a good year. I don't feel like answering the message but at the same time I am curious to know what is going on. What do you think I should do. Thanks for the help. Sometimes its good to hear others opinions so please be kind and supportive.