"Old man" Noah

Can anyone please tell me why the stuff I draw on my dry erase baord at work always comes out nice and in my sketchbook it looks like crap? I'm thinking it has to do with me either using a pencil or pen as opposed to a marker. Am I just more inclined to take chances with a big fat-tipped marker? I do find myself mulling over details with a pencil or non-photo blue outlines.. Hmmm. I'm going to have to explore the "fuck-it-just-do-it" mentality of marker drawings.

This is why I love my dry erase board at work.