This is the 126th most frequent Italian word.
davvero
"Really" or "truly."
'Davvero' here emphasizes the extent to which the subject (you) did not expect the surprise.
Davvero non ti aspettavi questa sorpresa!
You really didn't expect this surprise!
In this context, 'davvero' strengthens the meaning of the question, emphasizing sincerity or skepticism.
Credi davvero che riusciremo a finire in tempo?
Do you truly believe we will finish on time?
'Davvero' acts as an intensifier of the quality described (extraordinary) in this sentence.