As a DIYer, probably much like you, it is a bit confusing as there is hot on both sides of the switch. Once you stop and picture what the diagram is showing you and run it through your head, it does make sense. I guess it's just odd to see the neutral going to the switch and having the 2nd/3rd languages on it too don't help either.
I'm still very much a noobie and I was confused that they call the black screw "common" yet show the line coming in as "hot". I thought "common" meant neutral and so was like...
Why doesn't it just say "black screw hot", top silver screw neutral, and bottom brass screw hot to device?" I guess thats why it says to call an electrician. 
A few months ago, I couldn't have told you what colors and how many wires were even in a box.I'm still very much a noobie and I was confused that they call the black screw "common" yet show the line coming in as "hot". I thought "common" meant neutral and so was like...
Why doesn't it just say "black screw hot", top silver screw neutral, and bottom brass screw hot to device?" I guess thats why it says to call an electrician.
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That switch does not have 2 constant hots. You have one hot feed in the upper left and the the "switched leg".... which turns the light off and on.....is one the lower right. So you have a hot and a switch leg.
More correctly, the BLACK screw should be labeled "HOT (Line/Supply)" and the SILVER screw should be labeled "HOT (Switched)".As a DIYer, probably much like you, it is a bit confusing as there is hot on both sides of the switch.
I guess it's just odd to see the neutral going to the switch ...