Please help re auto-curve line altering feature

Question

to all Illustrator artists and experts: Can you please tell me the name of the Illustrator auto-curve line altering feature and how to adjust it or turn it off?  When I draw a line, and want that line not to be a perfect curve, when I complete the line Illustrator automatically alters it to make it a perfect curve.  This is changing my original line from what I intended to a homogenized curve I didn't intend.  Thank you for any help you can provide!

Answer 1

can't Illustrator simply save each part of my various movements as I draw the line - without "snapping" them all away
DoubleClick the Pencil or Brush tool (the tool icons in the program, not your hardware stylus) and turn off the Edit Selected Paths option. (This is a one-time setting. You don't have to revisit it each time you draw a path.)
You must use the Pencil tool or the Brush to achieve the results you desire. The Pen tool is specifically made to produce Bezier curves.
For clarity: All of the path drawing tools in Illustrator (including the Pencil and Brush) draw Bezier curves. They just employ different user interfaces for doing it.
The Pen Tool (the software tool in the program, not your stylus) employs an interface intended to allow you to explicitly place each anchorPoint and curve handle exactly where you want it. That's its purpose. So there is no "smoothness" setting for the Pen tool. The Pencil and Brush tools try to programmatically and automatically construct Bezier curves by interpreting the bitmap "path" you scribe by stroking with the pointing device. Therefore, they have Smootness settings to alter the interpreting algorithm.
That's pretty much standard practice across drawing programs like Illustrator.
There are a few commands (Roughen, Zig Zag, etc.) in the Filters (CS3) and/or Effects (CS4) menus to alter the jaggedness of selected path(s) after you've drawn them.
Generally, though, I agree with the comments of others: You need to sit down with the documentation and work through learning the program. Franky, I would add that you'd be better off doing that without using a stylus, just to minimize confusion. If you work with a mouse, you'll know what the program is capable of and how results are supposed to be achieved. Then, when you use the stylus, you'll be better able to discern whether a problem is due to a limitation of the program, or if it is something about your stylus settings, or just the small handful of stylus-supportive features in the program.
JET