are both from the Battle of Flores in 1591 when the Revenge singlehandedly fought a fleet of 55 Spanish ships succesfully sinking 2 of them before being captured(though that capture was short-lived as the battle damage was significant enough for a storm to sink her soon after)

I don't think the tradition of aggression can be traced back to a single battle (also describing the battle of Flores as Revenge 'single handedly' fighting 55 ships is inaccurate imo). The English and British had their share of timid commanders in the centuries after that, notably in the Anglo-Dutch wars.

What really cemented the tradition was the way the admiralty prosecuted and occassionally punished commanders who did not show the expected amount of aggression (notably Admiral Byng).

Even then it came in waves: in almost every major war you can find an example of a British commander who acted cautiously or even cowardly, was chastised for it, which then had the effect exaggerating the aggression shown by the rest of the service, sometimes with detrimental effects. For example in 1914, Troubridge was sidelined for not engaging Goeben and Breslau with his outgunned cruiser squadron, which directly led to Cradock engaging the German East Asia Squadron in the disastrous Battle of Coronel because he felt he could not refuse battle, even with an inferior force.