Trying to learn Illustrator, I couldn't wrap my head around the pen tool entirely. I cannot seem to control the centering of the curve that results from 'holding down to create a new anchor point'.
If your two pen points are parallel vertically or horizontally you can make a perfect 45 or 90 degree arc. This opened my eyes about the pen tools usefulness and gave me confidence that it's easy to control.
In addition to perfect curves you can quickly generate the exact swoosh you want, like the nike swoosh, by clicking once at swoosh beginning then clicking and holding at swoosh end and tweaking it into position. If you are not satisfied with your curve at all you can adjust it to any curve with the handles.
For truly rambling random lines you need to use the pencil tool.