1) That guy is hopeless. All my admonitions are like water off a duck's back.

2) The scolding ran off him like water off a duck's back.

3) Criticism falls off her like water off a duck's back.

4) Their criticisms of his talk rolled off him like water off a duck's back.

5) Advice and correction roll off him like water off a duck's back.

6) He has such a high opinion of himself that criticism flows off him like water off a duck's back.

7) Jack't care what people say. Criticism rolls off him like water off a duck's back.

8) To the seasoned campaigner, the remarks of hecklers were like water off a duck's back.

9) He always forgets something which his friends said, maybe's like water off a duck's back.