The most common and most likely answer to this crossword clue is the 8 plus 6 letter word IDENTITY CRISIS
I
D
E
N
T
I
T
Y
C
R
I
S
I
S
More clues leading to the result IDENTITY CRISIS
Buddy explains!
The straight part
We know that "wondering who one is" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case wondering who one is = identity crisis.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.