Red Bull Racing boss Christian Horner has praised the mental fortitude of Max Verstappen, saying the F1 star is able to quickly deal with and move on from setbacks.Despite Verstappen leading the championship table for the 2021 season until the most recent race, there have been plenty of ups and downs already.Notably, several of the biggest flashpoints have involved the Dutchman and his big rival Lewis Hamilton, the reigning champion.At the British Grand Prix in July the two came together early on, resulting in the Red Bull racer crashing out on the first lap before the Mercedes man went on to win.That caused huge annoyance for Verstappen, says his boss - but he was able to put the issue from his mind to continue focusing on the season and the remaining challenges ahead.Max was incredibly frustrated about the collision with Lewis in England and the result, Horner said.He had worked very hard that weekend, had already won the sprint race and had a good chance of winning the GP. Instead: contact with Hamilton, 51g crash, hospital, opponent victory, but on Monday he said to me, 'If I could do the race again, I would win it.' And then he left that behind.Since then, the pair have again clashed at Monza, with both drivers this time suffering an early exit.Verstappen had won back-to-back races in Belgium and Netherlands before that, but most recently Hamilton won the Russian Grand Prix with Verstappen second, claiming the 100th win of his career in the process and moving two points clear at the top of the driver standings.