CEO Secrets: O2 Telefonica UK boss's tips for success
28 March 2016 Last updated at 05:37 BST
Ronan Dunne, head of O2 Telefonica UK, offers the business advice he wishes he had been given when he started out, for the BBC News series, CEO Secrets.
BBC News caught up with him at a panel discussion exploring Irish leadership that took place at the Irish Embassy in London.
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