Yes, this is where the term 'half-cocked' comes from.

It varies with double action (DA) revolvers, but basically all single action (SA) revolvers work like:

You pull the hammer half way back, to half cocked, to revolve the cylinder.

You pull the hammer fully back, to fully cocked, for the trigger to be able to loose the hammer and thus fire the bullet.

So, if you are 'walking around half cocked', that means you are literally carrying around your weapon in a state where it is easier to fully cock and then fire it, (because you literally dont have to pull the hammer as far to get it to fully cocked), thus it implies you're basically ready / looking for a fight.

To de cock a fully cocked SA revolver, you pull the hammer back even further than fully cocked, press lightly on the trigger, and then carefully lower the hammer to rest position.

This kind of action mechanism is also what allows 'fanning' to be possible:

You just pull the trigger slightly, (the trigger has multiple stages), and then fan the hammer / fully pull the trigger.

Each full 'fan' of the hammer will bring it to fully cocked, and because your finger is now fully pulling the trigger, the hammer will immediately fall and thus fire. The fanning also of course pulls the hammer past half cocked, so the cylinder is revolving one click each time as well.

(At least this is my understanding of how one does 'fanning', I may be slightly wrong in some way, I've never fanned a revolver myself as it is... basically just a kind of trick shooting that is very much not recommended for a typical shooter)

Now... with double action (DA) revolvers, this is different.

Because with a double action, a full pull of the trigger basically pulls the hammer back as well, instead of you having to do that with your thumb.

So as you are pulling the trigger, you get to half cocked, revolving the cylinder, then fully cocked, which also is the point where the hammer is let to fall and thus fire the weapon.

It can get even more complicated with SA/DA, where its kinda both at the same time... there are different variations with different specific procedures for de cocking different kinds and models of revolvers.

And, you can get even more complicated than that, with say the Chiappa Rhino, or the Mateba Semi Auto Revolver.

So basically, broadly, you're not wrong / mostly generally right, but its even more complicated and depends on the specific kind of revolver you have.

it's probably really cheap and reliable to build it that way? that's what i always assume when i hear "dumb" design for some products

You also can’t disassemble a Glock for cleaning without pulling the trigger.