How important is mental stimulation in a relationship?

I met this guy 2 months ago and we’ve been talking almost every night and seeing each other once a week on weekends. He’s a great catch! He’s a gentleman, handsome, a very good guy, responsible, smart with decisions he makes, same views, makes me laugh, adventurous, open-minded, and goes after what he wants. Sometimes we even stay on the phone for hours just laughing and talking about random things.

Here’s the flaw, even though we can have conversation I feel like he doesn’t hold a very stimulating conversation that makes me think and challenges me. He sucks at explaining his perspective and when I ask for his opinion on things he doesn’t know how to elaborate how he feels or why he thinks that way. If he could just explain his perspective and thinking then I would be happy because seeing things from someone else’s eyes makes you learn a lot and think differently.

Is it possible to teach someone how to express their opinions and thoughts? I notice it is a struggle for him and he doesn’t know how to do it. Doesn’t know how to elaborate.I know how frustrating it feels to not know how to explain your view points but some how I learned. I don’t know how I did though, haha.