If she is the only one that told you that i would not worry about.

You can only get more mature from the experiences that you will have in your life. If you want to try to do the right thing just try to think more careful any decision you make, don't do silly things and think of other people instead of just yourself all the time(i am not saying that thats what u r doing).

"Immature" is a vague generalization, it's good to get specific. When you say you question your maturity, what does that mean exactly? What expectations or standards do you have that you're not meeting, or that you think you're behind the curve on? Nobody is fully mature: life is a process of developing in multiple areas simultaneously. So someone may be very advanced in (for example) processing their emotions, while still behind their peers in logical reasoning. It's not an all-or-nothing proposition. If you can realistically evaluate yourself in various aspects of development, then you can start being proactive about it, and accept yourself at the same time: you are where you are, there's not much more to say about it except to tell the truth about where exactly that is at the moment. The other thing that stands out about your question is that I suspect you're looking outside of yourself for indications about whether or not you're OK -- you apologized to the ex, and now you're asking us. The bad news about that is that it will never work: the only person who can really establish your "ok-ness" is you, and that normally doesn't happen until someone begins to take responsibility for their life in a comprehensive way... i.e. a sort of "Oh, I see... nobody is coming to rescue me... nobody is going to live my life for me... nobody else is going to create my future... nobody else is going to be able to tell me what's good or bad...", etc. That cold, hard splash of personal responsibility is probably the entry point to the sense of "maturity" that you're seeking, too. :)

Your ex? Fuck that dildo. You're a good person. He can suck it....How's that for mature?

Everything is relative. I wouldn't be concerned over what your ex said. Your ex may simply have been saying anything they thought might hurt you. If you think you want to be a more mature person, there's lots of books, online sources re personal development available.

How old are you? I'm 71 and I'm still "immature" about some things. Just because someone says something is true, doesn't mean it is. What, specifically, did he give you as examples? Was he perfect? Mature at all times? Fair at all times? Honest at all time? After a year I think you should simply move on from thinking about him..he is yesterday's news..you are living your own life today. Happy Thursday! :)

The fact that you apologized and still reflect on this tells me that you are mature. Perhaps your ex was speaking about a specific thing you said during the breakup. And remember, we are never at our best during a time like that. Maybe you were a bit immature or maybe your ex was lashing out. In any case, I would not put a lot of stock in it now.