Why is lightning forked?Why can't it travel in straight lines?

Enlightenment here:-

DISCLAIMER:

I'm probably wrong, I don't know the actual answer, this is just what makes sense to me in my head but I don't know if I'm correct.

Lighting occurs when there's a high potential difference between the Earth and the clouds or whatever's up there. The lightning jumps down to the Earth travelling via electrons in the air. The electrons aren't in pretty straight lines, they're all over the place. That current (the lightning bolt) just wants to get down to the Earth ASAP and will take the easiest path which sends it in all directions.

Forked lightning is not just cloud-to-ground lightning, although it's the most commonly observed. Forked lightning can also go from cloud-to-cloud and cloud-to-air.

Lightning traces a forked path toward to earth because the channel in which it travels seeks out a path of least resistance related to air density between:

1) a charge source and the ground

2) two charge centers of opposite sign in the thundercloud

3) a cloud charge center and the surrounding air

4) charge centers in adjacent clouds.

it's drunk