Since 2003, Jeremy Vine calculates he has taken more than 25,000 calls from his BBC Radio 2 listeners on topical subjects – big issues and small ones: on life, love, lollipop ladies and poisonous plants; on Brexit, Trump, Blair and Cellophane. But what have the callers told him? Often hilarious, he shares anecdotes from What I Learnt and explains why we should listen to what the callers have to say.