Mechanical engineering is certainly not a desk job, if you go into the right field. Mechanical engineering is a very difficult major with 4 semesters of calculus, a ton of thermodynamics, a ton of physical science type classes, some programming (Matlab) and a smidge of statistics. A mechanical engineering degree will take you a lot of places, but you have to be dedicated to get it and you have to know your math. You have to not like sleeping, too. If you want to get out in 4 years you're going to be doing a lot of all-nighters in the computer lab.