"Just curious, why have you texted? is that all?"

I texted one of my mentees couples weeks ago. Just to check in, how is he doing. We used to discuss about many of things during my tenure as his mentor. I was just in a sudden have a thought about him. So, I texted. 

I think it's because usually our relationship much more education-related matter. I took care of his study and something related to it. So, most of our texts are related to it, business matter. He laugh though that he asked me that question, it's simply because he doesn't really text and rarely got messages from others. 

But this thing happened not only once. I experienced it few times. The question of "why you texted me?" came after I asked "how are you?". 

Is it weird that you text person that you know without no intention towards business matter or can-you-help-me kinda thing? Just text because suddenly you were on my mind, and I was wondering how are you. That's all. 

Well.