를

Slipped into a negative for emphasis

All eight of these lines are the same construction: a verb, then 지, then 를 wedged in before the negative. It adds weight and a note of frustration — he still hasn't put the atlas down, I could never smile openly, our kids just couldn't memorise it, I should stop myself but I can't. Without it the sentences mean the same but sound flat; with it, the speaker is pushing against the situation. This is the object marker borrowed for emphasis, not marking an object.

Register: casual, spoken