Sylvester Stallone knows that people, fans and critics alike, may be cynical about his sixth “Rocky” installment, “Rocky Balboa.” Especially after 1990’s “Rocky” tanked critically, financially, creatively — in pretty much every way.

“Not ‘may be.’ It’s what level of cynicism,” Stallone quips, laughing in a Four Seasons Hotel room a few hours after donating several pieces of “Rocky” memorabilia to the Smithsonian.