From the perspective of a student pilot, the de Havilland Tiger Moth was a relatively stable and forgiving aircraft to fly, possessing few handling vices and being generally supportive of the odd silly mistake by the novice pilot. 
It quickly gained a reputation as being an ‘easy aeroplane to fly, but a difficult one to fly well’, qualities which seemed to make this the ideal aircraft to serve as a primary/basic trainer for large numbers of pilots destined to fly operationally during WWII.
 At the start of the war, the RAF had around 500 Tiger Moths in service, but would requisition hundreds more from flying clubs up and down the country.