When my kids were little, I'd sneak into the kitchen and turn the clock ahead one hour to get them to bed early. Back then, not every device and appliance had clocks on them or I'd be in trouble.
When was a time you had to be "sneaky?"
In secondary school, I had 'food technology' lessons with the most horrible teacher imaginable! One of the things we had to make was pastry, and mine went very wrong and there was no way I could use it (we had to make one large batch to make other stuff like apple pie etc with). Therefore, I had to make more pastry at home, and then sneak it into lessons, using the same type of freezer bags and everything so my teacher wouldn't know!