I got started back when I was about 13.
Playing with high voltage and the usual fascinating electronics stuff, got my fair share of zaps.
Saw a lab laser at school, it was a hene. Oatley electronics were selling both potted supplies and kit supplies, along with the laser tubes. I bought a 3mw siemens tube and a kit supply (love DIY).
Then I shoved the whole assembly into a poly pipe and powered it off a 12v alarm battery. Looked very star trekish, but didnt do much except project a red dot.
Then came the argon and sams laser faq. I had an NEC GLG 3030 laser without a power supply. Saving my pennies I built a huge argon supply from 2 500va toroids, a pass bank of 10 2n3055 transistors and an opamp or 2 for current regulation. MkI blew up because I did it on veroboard, but MkII was on proper etched PCB and worked well, then someone stole the laser system out of the club it was operating in (along with the fogger). It did around 40mw singleline, and used a very basic scanner - one axis that moved in time to the music, but back then it was pretty impressive.
Next came my first green - a $30 laser pen off ebay - its dead now but I still have it, and had oodles of fun with it. It would pop balloons and light matches, - was probably overspec, rare for an ebay pointer.
I wanted more power so 2 years ago I saved up a load of cash and bought a 1 watt green module. Had I known now, I would have opted for analogue modulation. That thing burns all sorts of things.
Finally just recently I acquired a laser projector (which is now my main interest in lasers, like Things), and a 445 diode from Dave, and constructed the "ugly duckling", a fairly ugly looking but very capable 1 watt portable module powered by a rc helicopter reciever pack. Yes, laughs all round when you focus the 445 and burn holes in the leaves at the top of a tree.
My interest i guess was sparked by the phaser used in star trek.