Sparkly- light brite didn’t say anything about marrying someone you don’t really like or getting married when you aren’t ready. He is just saying that you might not have to be “mature”. From the context, I understood that he is talking about someone who is ready to get married, but who still has growing to do. However, he is mature enough to build a relationship with someone and grow together with them.
I agree with light brite. But at the end of the day, these things really are very individual and depend on the individual, his background, and his life circumstances. There is absolutely no one right age to get married. Some people should get married at 18 and others at 40.
The one thing that is true is that it is Torah hashkafa to try to get married as soon as possible (stress on the word possible by which I mean acc. to what makes sense for the particular person). This is what Chazal say. And what Rav Chaim Kanievsky, Shlita says also.