Just because we were friends in high school, that was 20 years ago, I am a different person now, and hopefully you are too. Please do not ask me for my phone number. I don't even talk to my current friends on the phone, but how would you know that when we haven't communicated in 20 years?
Don't take it personally. I am not who I was in high school. It is good to hear from you, but 'picking up where we left off' is not as easy as it sounds.