Prince Harry has revealed he suffers from crippling nervousness before he has to speak in public.
He said: "Despite the fact I laugh and joke all the time, I get incredibly nervous, anxious actually, before going into a room full of people when I'm wearing a suit."
Speaking as part of a drive to reduce the stigma surrounding HIV, the prince added he was worried people would look at him more after his confession.
But he urged people to get involved with the #FeelNoShame campaign and reveal their secrets online.
Speaking earlier in a video posted by the charity Sentebale, a charity which helps vulnerable children from the African nation of Lesotho, Harry said the #FeelNoShame campaign he was joining was designed to encourage children to discuss their health concerns with others.
The prince said this World Aids Day would be turned into "a day in which noone should feel any shame about their secrets".
"Myself and many others will be sharing secrets of our own throughout the day, and we are asking everyone else to do the same," he added.
Among others to have joined the campaign is former world boxing champion Ricky Hatton, who revealed his lifelong fear of cats in a clip on YouTube.
Actor Ricky Tomlinson admitted he gets a professional cleaner in to clean his house and then tells his wife he's spent hours and hours doing it himself.
Nicole Scherzinger said she sometimes feels she is "not enough" and "doesn't fit in".
Actress Gemma Arterton also got involved, revealing she has never seen the films Star Wars or Back to the Future.
Comic and Little Britain actor Steve Furst admitted fooling his five-year-old daughter into leaving a Disney Princesses On Ice show early because he found it "painful" to sit through.
"I suddenly thought my daughter's five, she doesn't know what a second half is, and I said come on, we're going home now and we walked back to the car and drove back to Hastings," he said.
People who wish to get involved can tweet their secrets using the #FeelNoShame hashtag and are encouraged to donate by texting FEEL01 £5 to 70070.
Find out more celebrity secrets at feelnoshame.today