Am I Considered youngster at 22?

Just out of your teens so yes you are young, but not incapable of taking care of yourself.

Not by someone who is 7 but certainly by someone who is 70.

In the year 1800, the life expectancy was between 25 and 40. If you lived in India at the time, it was closer to 25. Ok Gramma?

Consider yourself blessed. 

Yes.  Only children younger than you think that you're a grown adult.  Even people in their late twenties consider you very young and callow (inexperienced, easily impressed or fooled).

But that's okay.  Every single one of us was there, once.  Enjoy it!!

well you're 48 years younger than me 

depends. are you a youngster to someone who is 3 years old? nope. to someone who is 86? yep