A little long, but it has all my "first" knives and a little background n them.
My first knife was a small peanut given to me by my grandfather when I started 1st grade. He said
"Now that you're starting school, you need your own knife. We can't have you borrowing one all the time." I had already been using knives under supervision for a couple of years, so no one was too worried about me having one. I was initially the only one in class carrying one, but after the pencil sharpener in the classroom literally blew apart and I used my knife to sharpen every one else's pencil, everyone (including my teacher

) seemed to get some small knife for Christmas.
My first fixed blade was a Western L46-5. I was helping my grandfather get the combine ready for maize harvest. His left shirt sleeve got caught in the chains/gears. He reached down, pulled out his Kabar 1232 and cut off his sleeve before he was injured. He looked at me and said
"That's why you carry a fixed blade when working on machinery. You'll never get a pocket knife out in time."
I replied with
"But Popo, what if it had been your other arm?"
He looked at me like I was speaking Greek at first, then he realized what I was talking about and he walked over, turned off the tractor and said
"Let's go."
We got in the truck, drove 3 miles to the Western Auto in town. They were out of 1232s, so he got the Western. A couple of weeks later, the WA owner called and told him that the "little Kabars" were in if he still wanted one. He replaced the Western with another 1232 and the first time he saw me after getting it, gave me the Western L46-5, saying
"If you're smart enough to come up with a question like that, you're old enough to carry a fixed blade."
Except when prohibited by law, regulation or workplace rules, I've carried paired fixed blades and paired folders. Because you never know which hand you will have to cut something with.
The first knife I bought for myself was a Buck 110 in 1973 when I used some of my HS graduation money to buy it.
As far as what kicked off my collecting of sharp and pointy things, that began when I came home from my 1st Class Midshipman Cruise between my junior and senior years in college. I had "free" money in my pocket from getting paid for 8 weeks of active duty. I knew that I needed, based on ready Navy Regs, as a small boat crewman (Boat Officer being one of the extra duties of an officer I experienced on cruise) either a USN MK1 or USN MK2. (Aside - by the time I was commissioned and started my active duty that the mandatory requirement had gone away, but the regulations had not been updated.)
So I went down to the local surplus store in College Station TX to see what they had. They had a 30 gallon barrel full of MK2s and another full of MK1s for $10 each. I picked out a nice MK2 (had to get the 7" blade over the 5", right???

). Then I saw this weird looking bayonet. The guy wanted $10 for it, as well. I asked him if he'd take $15 for the pair. He agreed. It took me a while to find out what I had was an 1869 Yataghan bladed Chassepot sword bayonet. I decided later that I wanted a MK1 as well. I went back and got one, talked the guy down to $8 for that one.
I still have everyone of those knives.
This coming July, it will have been 40 years since I started collecting military knives, bayonets, swords and then non-military knives. I've bought way more than I have sold or given away, and I've given away more than I have sold.