Deulofeu has been in scintillating form since returning to Goodison Park on a permanent deal after his initial loan from Barcelona two seasons ago.
"He has matured," Barry said.
"[He doesn't] let anything go to their heads. [He doesn't let success affect him.
"That first loan of Gerard's was tough but he's come back to a club that he knows, with players he knows and he is confident straight away. He knows this is his time to do it."