The 22-year-old retained his 50 metres freestyle and 100m butterfly crowns in Gwangju with plenty to spare, before leading the American mixed 4x100m freestyle team to a new world record for good measure.
"I probably sound like a broken record but every time I race I always look for the bad," said Dressel, who became the first swimmer to capture at least six gold medals at two world championships.
"It wasn't easy tonight. I don't want it to be easy, I really don't."
But despite leaving Brazilian Bruno Fratus and Greek Kristian Gkolomeev for dead in the 50m free, which he won in a championship best 21.04 seconds, Dressel was still fretting about his start.
"It was so bad, I wish I could have that one back," said the tattooed pin-up, who swept to seven gold medals at the 2017 world championships in Budapest.
"There's a lot of parts of my race that I can improve on," added Dressel in a comment that will bring a collective gulp from rivals in the run-up to the 2020 Tokyo Olympics.
"I've never had a perfect race in my life and I certainly don't think I will."
In reality, Dressel is beginning to look like Michael Phelps in his pomp.
And, whisper it, maybe even better.
Dressel obliterated Phelps's 10-year-old 100m butterfly world record in Friday's semi-finals, clocking a jaw-dropping 49.50 seconds to lop 0.32 off the American legend's old bodysuit mark and rob him of a second world record in 48 hours.
The final was little more than a formality as Dressel exploded from the blocks in a signature fast start to win in 49.66 - only the second-quickest swim ever.
"It doesn't just come together by accident," he shrugged. "It's just about getting in every day and learning event to event, practice to practice.
"But I'm glad it's over - I certainly don't want to swim any more than this tonight," added Dressel, who could pocket a seventh gold - and eighth medal of the week - in Sunday's 4x100m mixed medley.
"Tomorrow I will be ready to swim one more, and one more fast."
The only blot on Dressel's copy-book in Gwangju was a silver medal behind Australia in the 4x100m mixed medley earlier this week.
But in the individual races, the American looks untouchable, also winning the 50m fly and retaining his title in swimming's blue riband event, the 100m freestyle.
Dressel's challenge will be to play down the massive expectation on him to emulate Phelps's record eight gold medals at the 2008 Beijing Olympics in Tokyo next summer.
"I've never been one to buy into all the hype," he insisted. "It's really just between myself and my coach and getting ready. But I'll be ready for it next year."