I almost did the same thing once when I had a gas stove. Made dinner, forgot to turn the lever in the back (it was an older model) and went to bed. Woke up in the morning (luckily), took a shower etc. Didn’t notice anything out of the ordinary and went to work. At 4pm my landlord downstairs calls me and says they can smell gas in the stairway. Fuck. They went in, shut it off and opened all the windows. I came home 3 hours later and the smell was still really intense. I could have killed not only myself but also caused the house to blow up and wipe out my landlords as well. Fuck gas stoves.