You were
-Britney
-Christina
@ your age...for example

My Age:21 years and 10 months old
What was britney doing at that age?
october 2003, Britney was next to release In the Zone album... Damn how fast!
What was Christina doing at that age?
october 2002,Christina released Stripped album...

This will give you a idea that at your age some people were already incredible succesful...damn

MY age: 19 years and 3 months
What was Britney doing at that age?

She released her third album "Britney in Nov of 2001

What was Xtina doing at that age?

Went on her first tour w/ Destiy Child in Oct of 2000 which I went to!

20 years and 9 months old:

Britney - I believe she was already finishing her break and recording songs for ITZ - just like now! :P

Christina - If I'm not wrong, she was about to release her Latin album!

25 y.o.

Britney: hanging out with Paris and showing her 'gyna to the world
Christina: promoting her not so successful 3rd album

My age : 16 years 7 months old.

What was britney doing at that age?
She just graduated from High School, got record contract. She recorded her first smash hit album, BOMT, or maybe had just finished then. And she's ready to release it!!!

What was Christina doing at that age?
She's just still a normal teenage girl. She hadnt even recorded her first album this time.