What decides who's normal

Sitting on a park bench, laptop on my knees, a gentle breeze caressing my skin, reflecting, thoughts wandering, thinking will I see my friend again today?    
     
I observe a man walk past, talking to himself, hands gesturing into the empty space in front of him, mumbled words I can not understand, and I think to myself.........    
                                                thank God I'm normal.    
     
A couple arguing, loud words flying, words that in my younger days would get my mouth washed out with soap. They stop, see me staring and she yells "what are you looking at, mind your own business", shooting dirty looks over their shoulders as they move on, and I think to myself....      
                                                thank God I'm normal    
     
An old woman with shopping cart, pushing all her worldly belongings before her, searching each trash can she passes, perhaps looking for remnants from better days and I think to myself.......    
                                                thank God I'm normal    
     
An elderly couple, holding hands, talking quietly, smiling at one another, I can see the many years spent together and I think to myself..............    
                                                 thank God, they're normal      
     
My friend arrives in his police car, walks over and stands in front of me, "Hi Jessie, enjoying the morning sun I see."    
"Hi Frank, how's the wife and kids"? I reply.    
"They're fine" he replies, " ready to go"?    
"Yes I'm ready, just let me get my coffee"    
Waiting patiently he adds, " may as well put your clothes back on while you're at it", as he thinks to himself........    
                                                     thank God, I'm normal