Awful bores at university become more realistic (5,2)
I believe the answer is:
Here is my best explanation:
'become more realistic' is the definition.
('sober up' can be a synonym of 'become more realistic')
'awful bores at university' is the subsidiary indication.
'awful' indicates an anagram.
'at university' becomes 'up'.
'bores' anagrammed gives 'sober'.
(Another definition for sober up that I've seen is "Become less drunk".)