Ever since Ringo Starr vowed, on a well-known cover of Buck Owens’s hit “Act Naturally,” that he’d become “the biggest fool to ever hit the big time,” the renowned rock ’n’ roll drummer has done all right for himself. As a member of the Beatles and as a solo artist, Mr. Starr has sold more than a few records, won some Grammy Awards and even had a minor planet named for him. But on Wednesday Mr. Starr will reach a very special milestone: he turns 70 years old.