The idiot kid is right. Tire levers should never be used in putting on
tires--only in getting them off.
I find it easiest to partially inflate the tube (just fill it, don't
let it stretch) before putting on the tire.
First I fill the tube, then I mount one side of the tire, then I load
the tube into the tire, and start pressing the second bead over the rim
using my thumbs, starting at the side opposite the valve. As I move
toward the valve, I let just a little air out of the tube, as needed.
This keeps the tube inflated and avoids pinch flats. You may need to
let more air out as you proceed.
Finally, you should be able to wrestle the last bit of bead over the
rim as you reach the valve. Reinflate the tube JUST A LITTLE, so the
tire is tensioned, then work your way around the wheel, pressing in the
sidewalls, making sure the bead is seated and the tube isn't caught
between the bead and the rim.
Once you've done this, you should be able to inflate to full pressure
with confidence.