Becoming confused as one ages (5)
I believe the answer is:
aeons
'becoming confused as one ages' is the definition.
'aeons' can be an answer for 'ages' (aeon is a kind of age). I am not certain of the 'becoming confused as one' bit.
'one ages' is the wordplay.
'one' becomes 'a' (a thing is one thing).
'ages' becomes 'eons' (eon is a kind of age).
'a'+'eons'='AEONS'
Can you help me to learn more?
(Other definitions for aeons that I've seen before include "Vast ages" , "Long periods of time" .)