Carnival (CCL -0.10%) (CUK 0.15%) was decimated when the COVID-19 pandemic hit in 2020, as operations were halted to help stop the spread of the virus. Revenue tanked, and the business had to take on more debt to survive with the fate of the economy being a big unknown. However, Carnival is firing on all cylinders these days.This travel stock has soared 202% in the past three years (as of July 22). But shares still trade a gut-wrenching 59% off their peak. At the current price, is Carnival a once-in-a-gener ...