Setting off the Alarm - oops

Yesterday was Day 1 of dog sitting for the cutie, Mabel, Jose's pup.  Jose is the greatest friend I have met down here!  He's out of town for the weekend and I get dog duty.  I grew up with a dog in the house, the best dog in the world, Baren, and I used to dog sit for an old boss all the time, so I know how to take care of a dog.  But for what ever reason I was really nervous about watching Mabel.  Maybe because she hasn't had tons of time to get to know me and trust me or maybe because she thinks Im trying to take Jose from her, haha but I don't want to mess anything up. 

I was also nervous about setting off the house alarm.  It's not hard - there are 5 buttons to push to disarm and 6 to push to arm.  Everything went great getting into the house.  Then it was time to leave.  I put Mabel away, set the alarm and left the house, all good.  Then I realized my keys were in the house.  Back in I went, causing Mabel to cry and I couldn't find my keys.  Remember how I said there are 5 buttons to push to disarm... yeah, I only hit 4.  The alarm went off.  I'm such an idiot.  HA.  The nice man at the security company called and we had a laugh.  Now I'm even more nervous.  It's not hard, I should be able to do this.