>>4I totally agree, and that is why I use the term, "mature," very loosely. I know I am less mature than others in multiple ways. But I am also way more mature than them in other ways.
For me, I would like to be with someone that I see as mature. I made the mistake of not really caring about it before and ended up getting burned. Of course if they show they are mature then I will reconsider them. So if it shows then maybe he will reconsider you as well. It may take some time, since everyone judges another in their own ways.
It might not even be due to the age as well. It could have been due to him seeing something else in you that he defines as a red flag.