There aren't as many in real life, we realise (5)
I believe the answer is:
fewer
'there aren't as many' is the definition.
I can't tell whether this defines the answer.
'in real life we realise' is the wordplay.
'in' says the answer is hidden in the clue.
'FEWER' is hidden within 'real life we realise'.
Can you help me to learn more?
(Other definitions for fewer that I've seen before include "in smaller numbers" , "Not so many" , "Less in number" , "smaller number of people" , "Reduced" .)