'GREETINGS!'

In preteens, 

I looked at people and smiled when I was asked to wish..

In teens, 

I looked at people and said, similar to 'Hello!' where I was asked to wish as well as I felt like I should..

In early 20s,

I looked at people and said, similar to 'Hi!' wherever I had to do so..

In late 20s,

I started addressing, similar to 'Uncle!' and 'Aunty!' whenever I met concerned people..

From mid 30s,

I started addressing, 'Sir!' and 'Madam!' whenever I met concerned people..

From early 40s,

I continued the habit of mid 30s but started calling people of my age and below by name..

From early 50's, 

Whatever I called others appropriate, I made sure people below me address me 'Sir!'

In late 50s, 

I doubly made sure myself calling all those above me wielding power, 'Sir!' and 'Madam!'

In early 60's,

I made sure I call people in power, 'Sir!' and 'Madam!' even the Juniors or earlier subordinates acknowledging rest as per decorum..

In late 60's, 

It was a mixture of words from me while greeting everywhere, With no great interest in anything beyond..

And 

Beyond,

It was, most of the times, silent nodding and smile everywhere for max time!

Keyword:

GREETINGS