Many 18yo skip university and go straight from secondary education/college to a flight school. They come out with a CPL/IR before the age of 20. Low cost carriers suck these people up from flight schools in great quantities whilst ignoring the huge supply of already very experienced pilots who could do the same job (but want/need a bigger paycheck). They then put them through a jet type rating. Four years at an airline like RYR as an FO, followed by one year as a captain will make him an ATPL holder with >4,000 hour total time and close to a thousand hours as a captain. He is perfectly eligible to apply for most DE Captain 777 jobs in the world. So yes it can happen, and it's the direct result of low cost airlines favouring young puppies over slightly mature ones.