Gareth Southgate understood why fans booed his side after a dismal defeat to Iceland that the England manager hopes will “really focus the mind” heading into Euro 2024.An expectant Wembley crowd let their frustrations known after an alarmingly poor performance in their last warm-up friendly against a side that will not even be at the finals in Germany.Southgate’s side were toothless in attack and porous at the back, with Jon Dagur Thorsteinsson’s fine early finish securing Iceland another memorable win against England.