David Letterman is unable to use his phone

London: Former "Late Show" host David Letterman has joked that he cannot use a phone since retiring from the show as he had an assistant do it for him for 30 years.

The 68-year-old TV presenter, whose show "Late Night with David Letterman" ended last month after airing for 33 years, admitted he struggled to use the telephone, reported Female First.

"As it turns out, after all these years of having someone make my calls for me, I can no longer operate a telephone," Letterman said.

The comedian, who is enjoying his leisure time fishing with his 11-year-old son Harry, said he is finding it difficult to know how to style his hair.

"I don't know what to do with my hair, either. But I'll never wear makeup again, so that's no problem," he said.