What is a Gurkha?
Back when the Brits ruled India, they recruited native troops, including at that time the Gurkhas. They started early, and they've continued for a long time. To give you an idea of how well-respected they are, the British Army circa the Zulu War considered them elite troops, at a time when the British Army talked down to
everybody, and being native troops and not English they had a perhaps greater hurdle to overcome then simply not wearing red uniforms. The truth of it is they had superior discipline to anybody and everybody. A regular unit would abort an attack or break in the open field if it took casualties of 5-10 percent, and aggressiveness was not a valued trait. The Gurkha Rifles pressed their attacks harder, you saw their backs only after they were dead, they were aggressive, and unlike regular British troops of the time they were not only excellent riflemen but very capable at close quarters as well.
Even as late as the Second World War the Wehrmacht in the North African desert rated the "day is ruined" opponents an infantry unit could have as the Gurkhas, SAS, and then the Aussies.
