Automatic Doors

I find it interesting that when I arrive at work on a bicycle, many people (most of whom I do not know) are willing to hold the door open for me.  "Oh, let me get that for you.", they say as they run over to help.  I often wonder if they would do the same for someone in a wheelchair. 

"It's alright, I have a system.", I respond.
"Are you sure?", they ask and they reach around or over me to hold the door open.  I appreciate their help, but sometimes they end up making the process more difficult.  I pay close attention to keep my bike tires from brushing against them.
"I do this every day.  I've been practising."

Occasionally, they stand back while I work my system, and then they say with surprise, "You do have a system!"

Yup.  I practise.