My knife hobby was due to 2 people:
The first was one of my friends who went trough a mallninja phase. Summer of sophomore year in high school, he bought a cheapo balisong and taught me and some of my friends basic flips. I thought it was so cool that I ended buying an Mtech Twist to learn more advanced tricks. My balisong craze ended soon after my parents found all the cuts on my hand. My friend then got one of those black-blade-tactical-tanto spring assisted knives (in a mall, of all places), and I was surprised to learn that his "switchblade" was actually legal. Back then, I couldn't use thumbstuds for my life, so I bought a spring assisted flipper, yet another cheapo Mtech. The handle scales broke after a week when I dropped the knife on the kitchen floor. That weekend, I found some scrap plastic, a drill, and sandpaper, and I made my own scales instead of getting a new knife. One small step for penny-pinching; one giant step towards being a knife nut.
Fast forward to summer of senior year. Spring assisted knives were all I cared about until I went to a police equipment store with another friend who was about to join the military. We walked in, looked around, and I almost couldn't believe how "expensive" some knives are. This weird looking knife with a hole in the blade...for $60?!...why would anyone buy that?! So dumb little me pulls out my knife then says "I have a spring assisted knife that can probably open faster than any of these!". What does my friend do? He says "no, there is a faster way" and waves out a CQC-7. Oh man. I spent the rest of the day on the internet learning everything I could about knives.
The other thing I noticed is that learning about knife steels actually helps me with my material science courses. I just had an exam in which I had to answer questions about a extrusion die made of D2 tool steel. I had the biggest grin on my face as I breezed through that section. D2? Why, that's right up my alley! Thank goodness for my recently developed interest in the HEST/F and Brous SSF.
tl;dr: Two friends: one who bought fun knives, and one who bought quality knives.