In my case, I would say the biggest challenge is to find the time to actually practice and draw as much as I'd like, since I'm on a hectic 8 to 5 schedule doing my regular work. But schedules aside, the transition can feel at times frustrating or like you have to unlearn and re-learn. I grew up drawing with pens and pencils on a piece of paper, and now it takes a bit of adjusting to not looking at the tablet but rather following on the computer screen whatever you're doing with your stylus. Also, you need to re-learn how to put enough little pressure when using the tablet, since pencil and pen require way more pressure over the paper unless you're shading. I've been lucky that the way into the software is actually not so different from the CAD environment. One of my first jobs was drafting with Autocad so I got used to navigating menus, using layers, adjusting pen widths, paper sizes and it's nice that most painting software also lets you use layers, so this wasn't hard to understand. I also grew up using perspective in my drawings so this is handy for trying to apply 3D effects of shadow, lighting, foreground and background effects and proportions. Right now I truly want to learn how to blend colors better, and my only available tools right now are Painter Elements 4, Photoshop Elements and Google's GIMP. Looking at many works around here it's easy to feel like Oh man! When will I be as good as that dude?..and so on..but then again you have to not compare yourself to others but rather, don't be discouraged and don't be agraid to experiment, and do, and practice and above all, enjoy your whole creating process.... cheers!