What exactly did he say?
Were you two close back then?
Or do you wish you would be now?
It's perfectly normal to have stranger anxiety or feeling awkward when meeting someone again out of the blue after a long time, especially when not prepared for it or being occupied with something else!
Some people can talk about anything and everything at the push of a button!
Others enjoy a proper conversation in a proper setting and environment.
AND you will never know what others really think about you!
You might even be positively surprised! Some people actually enjoy the company of good listeners and reserved people!
He might have noticed that you are insecure or not self-confident or didn't talk much about yourself! SO!? He didn't run away in disgust but stuck with you!
It's only the truth and there's absolutely nothing wrong with it! People are different and you are who you are!
We come across best, when we don't try to be somebody else!