It took Mark a few years to get used to being a human. When first asked how he liked it, he would respond, "Not at all.  I would much rather be an alien or a robot, or at a bare minimum a cyborg". Aspirations to become an astronaut were quite indicative of his overactive imagination...with little basis in reality.  

Thankfully, he soon learned to harness his imagination for good. Boxes were not boxes, but airplanes. Hair dryers were not hair dryers, but boat motors in the tub. (Sorry mom) Motorized toys were not motorized toys, but valuable sources of motors which - once extracted - could have a plastic margarine lid taped to the top (propeller)  and provide horsepower to the airplane. Sisters were not sisters, but enemy forces.

Speaking of sisters, he had many.  Four to be exact. With no brothers in sight, the sisters fell into one of two categories. Those who would put up with being dressed in army fatigue, and those who would not.

His childhood involved creativity of every kind. Lying awake at night, he would dream up businesses, with the expressed purpose of designing a corporate identity the next morning on his pad of graph paper. No, none of these businesses were financially viable, but they sure had some sweet logos, and carbon copy paper ensured that he had a hundred copies.

Making home videos with Tyler and Kendrah was a regular pastime, you know those ones where you make the person disappear by stopping the recording, removing the subject, and then starting the recording again - sans subject.