My two worst cuts did not involve knives, but a table saw and a garden spike.
For the table saw, I just ripped the pad of my left thumb 90% off. Most grew back but I have a weird thumbprint. Ran into a little problem when renewing a military security clearance later as the print no longer matched what was in the system. There was a bunch of paperwork required to "correct" the system record to reflect the "new print" and justify the need for a change. Let's just say a lot of alphabet agencies got involved.
The garden spike incident occurred back when I was about 12 years old. Out back, there was an abandoned alley that ran along the back of the lots on my block. It was about 30 feet wide and totally overgrown for nearly 1/4 mile. All us kids called it "The Jungle". We had "tunnels and caves" throughout the entire length to play in. About 50 yards from my house, there was a particular china berry tree that was half blown over and it made an absolutely wonderful ramp to run up and then jump off into a mass of honeysuckle vines.
After many of us had jumped off the tree and into the vines for weeks, one day when I jumped off, I managed to come down on a 12" garden landscaping spike that was driven through a chunk of 2x4. The spike went through the bottom of my tennis shoe, my sock, my foot and then the sock and shoe again.
While I was trying to extricate myself from the vines, my best friend ran to my house to tell my parents. Fortunately, he got there just moments before they were about to drive off for a business meeting in Austin 30 miles away.
Have you ever tried to climb a 4 foot high chain link fence with a 2x4 nailed to your foot?

It's NOT easy.
I hopped the 50 yards on 1 foot, crawled in the car and my parent took myself and my friend to the hospital. He wanted to go along so he could see his father in daylight. Dr. L was our family doctor and he seldom got home before dark.
My parents dumped me off, used the hospital phone to call my grandmother. "We just dropped Wayne off at the hospital with a nail in his foot. We gotta get to Austin for a meeting. Come pick him up."
Dr. L took one look at my predicament and said "Well, I've never had one of these before.".
He pulled his keys out of his pocket and told Michael to go get his tool box out of the trunk. While Michael was getting the tool box, Dr. L carefully destroyed my tennis shoe with scalpels. He dulled a dozen or more cutting through the rubber and canvas. After the tool box arrived, Dr. L used his hacksaw to cut the spike between my foot and the 2x4. Then he used a file to smooth the butt edge of the spike, and pulled the spike on out through the top of my foot.
Dr. L proceeded to pull leaves, weeds, chunks of tennis shoe sole, dirt and bone splinters out of my foot. Once, he grabbed a bone that wasn't a splinter and tried to pull it out. Ouch!!!!
His only comment on that was - "I guess we'll leave that one in there."
The entire time he was working, he had a running commentary on what he was doing, interspersed with acerbic comments about the stupid predicaments kids could end up in.
Then he stuck a funnel in the hole in the top of my foot and said "This is gonna hurt."

and poured about a gallon of H2O2 through my foot until no more trash and very little blood was coming out the bottom of my foot. And YES, it did hurt.


It took a while to heal and I spent the rest of the summer NOT swimming in the town pool.

Long term effect was a significant reduction in how fast I could run. I could still run forever but not very fast.
Oh, about Dr. L's somewhat rough bedside manner - he was a good old Texas-Czech farm boy for whom English was a second language who went off to WW2 where he flew 30+ missions as a waist gunner on bombers, then came home to go to Med School. He got married in England and when he transferred home after the war, he managed to ship his .50 cal waist gun home, disassembled in a box as part of his wife's household goods labeled "Pots and Pans". Not exactly your "typical" small town doctor.