Thousands of people in Spain attended events on Monday to mark the 20th anniversary of the worst terrorist attack in the country’s history, when 10 bombs went off on full commuter trains in the Madrid region, killing 193 people and injuring almost 2,000. “This date unites us in a memory that is both personal and public at the same time, and that does not wane with time,” King Felipe VI said at a ceremony to mark European Remembrance Day for Victims of Terrorism which falls on the date of the Madrid bombings but recalls all terrorist attacks. Prime Minister Pedro Sánchez said remembrance had to…