Dad

I have a patient that comes into my store.  He is in his late 50's.  The funny thing about him is he calls me "Dad".  Why does he call me dad? He calls me Dad because I'm the one he comes to when he has questions.  Not just drug questions but any questions.  He asks me opinion and my advice several times a week.  We have developed a close friendship, despite being over 20 years older than me, he still calls me Dad because I am some he looks up to and respects.  It feels really good to be his Dad.