Phone call

So I just had a phone call from the exN.

I know I shouldn't Of answered it but he said he 'had something to talk to me about'

So surprisingly it was a civil conversation, he asked me how things were going with college, work etc

Nothing was mentioned at all about us ....

I don't understand why he called? I'm unsure how I feel about it. Guess its nice to know he wanted to talk to me but I honestly didn't have much to say. I feel like I care less ....