Search Results: ex boyfriend kissed me

So I have an issue...
2 guys in my life have already ended things with me based on the issue of "maturity"
My ex-boyfriend (23) and a guy I dated briefly afterward (23).

-My ex-boyfriend and I were on and off for a while b/c of his commitment issues + he was unsure of me. He would end things and come back to me multiple times because "there were things he liked about me and things he didn't like" One of the things he didn't like was that I was younger, still in school, and didn't have as much life experience
-The guy I dated briefly went out with me for 4 dates. Later on, he confessed he didn't see us dating because "maturity-wise him and I were at different spots" He even gave an example of immaturity based on my part with the first time we kissed which was was "awkward and weird"

I am a 21-year old female that works two jobs, is in college full time, is saving up for an apartment for the end of the year, and I already have my career goals in mind.
I didn't date in high school because I wanted to focus on school and I also didn't even think guys liked me + I had very low self-esteem for dating
I just started seriously dating around 2 years ago... do you think because I dated later on in life that guys that are older think I'm immature? Do I just need more experience with dating?

I feel like for a 21-year-old female, I know myself pretty well. I'm loyal, sweet, caring. supportive, open-minded, creative, have hobbies and am social
However, I can also be emotional, sensitive, shy, passive-aggressive, needy, and sometimes lazy.

Is there something wrong with me or am I just picking wrong guys? Or maybe it's both...