As a one who has been called a mechanical engineer, maunfacturing engineer and worse...it is my experience that mechanical aptitude is genetic to a large degree and some just won't ever get it. We ain't all born equal, people....
However, to a small degree it can be learned sufficiently to do most tasks and stay out of trouble. And trust me, a degree in ME does not impart any APTITUDE in the least. We all know the story of the Mechanical Engineer who designed wonderful bridges and airplanes and such but didn't know which end of the screwdriver to hold.
A former boss (ME) always gave interviewees a simple test: given a sheet of paper with a top, right and front view of a moderately complex block shape, draw a reasonable isometric of it. More than a few degreed MEs simply couldn't do it.
But if a genetically-inclined mechanical genius isn't exposed, trained and given a chance, he/she won't stand a snowball's chance of being good at it.
Conversely, all the fancy tools, books and schooling in the world won't make a mechanical genius out of someone who just doesn't have the genes. And that's ok, we need accountants, too.