Any Physicists or Electricians here?

[TheNihilanth]

In the case of a 3 phase line, A, B and C lines carries a voltage, each one of said lines has a reference level (ground), and when you touch one of those lines (any of the 3) and you are touching ground you get electrocuted, fried, you hang in the sneakers, in other words you are dead.

You can even be electrocuted without touching anything if you are near to a high tension place (eg. air connection...).
We can illustrate what you said by this image below, instead of letters A/B/C I used numbers 1/2/3 (dedicated to Assault Cube FTW):

PS: Sorry for the image quality, I have again a prehistorical phone with 2.3MP!

Yes that's 100% correct.

And this is why one must not camp near the transformers in ac_power, kids.