Your ex-girlfriend held all her emotions into herself. She is probably very introverted and a perfectionist. You might be outgoing, however, you are not outgoing enough to have her speak out to you. She is a perfectionist. Therefore, everything seems o.k. for you while you are definitely not perfect for her although you don’t even know what’s wrong. Thus, I think the first thing you need to do is to know yourself, know your weaknesses. You can’t find answers from your ex-girlfriend, but you can find answers from your good friends and family members. Also, I would suggest you not to date the same type of girl in the future. The reason is to date such girl you must be very expressive to an extent that she is willing to at least be expressive to you. The second reason is if you think you are an ordinary human and can’t be perfect then it’s very hard for you to meet her criteria. It might help if you date someone like you, who’s a bit more outspoken, not so perfect. In this way, you know each other more and at the same time you know yourself more from the other person, especially the weaknesses. A non-perfect person is usually more broadminded than a “perfect” one, then the chances are, you are both willing to change yourself a little bit when you know what’s wrong and meanwhile you are both able to accept the other one.