Got bit for the first time tonight...

[GibsonGM]

Isn't current at least as much a concern as voltage?  Or rather power?  My last job was at a place that made specialty CRTs (mil/aviation) and I worked with 7~40KV anode voltages daily, though currents were measured in microamps.  Got zapped a few times here and there (it will reach out and get you at those voltages!) but nothing ever felt nearly as serious as 450V from a tube amp.

Yes, ability to deliver current is why you don't die when you touch a door knob in winter after walking on a carpet...I believe it takes like 30,000 volts to jump 1 cm....but there's no current there.

But..."It's volts that jolts..it's mils that kills"...it only takes something like 10mA thru your heart to potentially kill you.  That's why they say "over 30V is high voltage"...the result of Ohm's Law done with 30V at typical skin resistance gives somewhere in that neighborhood.  I could be off a little on the exact numbers, since I'm just remembering this from an old Navy electronics manual I read 15 years ago, but that's the idea.
So your microvolts weren't up to the job.   

With 15A to 20A typically available thru mains, any time you're messing with it you're well into the kill zone.  You'd be gone long before the breaker tripped...

Geez - be careful, Karbo, LOL!  I used to like to use those to make Jacob's Ladders. 

[karbomusic]

Yes Sir Mike!

That really taught me a lesson and happy to be alive 39 years later. Yes, Jacob's Ladder was it's main use - That transformer was my ace in the hole for an A+ in science class for several years.

[PRR]

> Geeeeeez, didn't any of you bother to learn to read in school?

This is the internet. Reading is rare.

> He was using rubber gloves, sweaty hands and all.

Practices vary. In my area, the cheapest (Class 0, 1KV) rated rubber glove costs $87. This is normally worn with *leather* gloves over the rubber for protection. {Edit: limited exception for Class 0 work requiring dexterity.) The rubber gloves must be re-tested regularly. Air-test daily, electrical test every 6 months.
https://www.osha.gov/SLTC/etools/electric_power/ppe_insulatinggloves_sleeves.html
http://www.mitchellinstrument.com/safety-and-personal-protective-equipment-ppe/insulated-glove-testing.html
https://hjarnett.com/services/rubber-glove-testing-lab/

I'm worried someone may get "braver" with gloves on.

In all small electronics, it is entirely possible to do all work without touching live parts. (Connection to an always-on Power Grid is of course different.)

[duck_arse]

If you ever take 30,000V through your chest, and live, you will become VERY careful how you handle electricals

I took 15k (or whatever made it) through my right arm, down my body to the cement floor when I was 15 ....

15 is a good age for your last jolt. I took the mains from one hand to the other, at the fuse box, when I was 15. school work experience - the apprentice I was working with came to see why I was swearing, and then turned off the main switch. he'd helpfully pulled the fuse (so he wouldn't get volts in the roof) so I could stick my finger in the holder.