“So why did you love her?” (Your ex)
If you say, “I don’t know” you’ll come off as daft and un-analytical, and suddenly your girlfriend will fear that you don’t even know why you love her. You can’t say, “I didn’t” because, well, yes you did. And your girlfriend knows that. The winning answer combines a little bit of self-deprecation to yourself and compliment to your new girl. Your girlfriend wants to hear that your being with her is an indication that you’re now a better, smarter person. So, in a way, you can tell the truth. Just not the whole truth. Pick out an element of your last relationship that didn’t work for you. Say, for example, your ex really played by the rules and wanted a 9 to 5 job, and you used to want that too. Then you realized you wanted to have the freedom to be more creative and pursue your passions. That says to your new girlfriend that she inspires you to be creative and pursue your passions. See how that works?