Do you become a Senior Citizen at age Fifty?

So I'm now a Senior Citizen

At what age do you become a, Senior Citizen?

A few weeks ago a friend asked me if I had gone on any of the, Senior Bus Trips.  I quickly informed her that I couldn't go because I was not a senior yet.  She looked at me and said, "I thought you were over fifty".  Yes! I replied but you are not a senior until you hit sixty two. At this she started to laugh and said no it is fifty and you are a senior citizen.  I was so upset I had to sit down.                                                                      

The next day I found myself a little depressed.  I sat on my couch and told myself, " you are old, you are a grandmother now with gray hair and wrinkles.  Later when I met my friend for dinner I told her that I had been depressed during the day.  After I explained that all of a sudden I realized I was old and that it had shocked me a little.  

Wouldn't you know she apologized for pointing out that I was a senior citizen.  She realized before I did    that the realization of becoming a, "SENIOR" was what had put me in a slump.                                          

I have decided to except the fact that I am a senior.  A senior meaning a person older than another and a person of greater rank, standing, or life.

On the other hand, " I am not a senior citizen".  The Webster's New World College Dictionary, Fourth Edition has an acceptable definition for a senior citizen.

Senior Citizen; an elderly person, esp, one who is retired.

I may be older than some but I am not elderly and I have not retired.

Do you become a Senior Citizen at age fifty?

I wonder what SSI will say the age to become a Senior Citizen is.