For those taking Adderall, what does it feel like when you're at the 'correct' dose? Did you have trouble finding the right one?

Started taking 20mg Adderall XR and so far it's only managed to make feel like I drank extra strong coffee the whole day. Increased libido and a bit of jitteryness, but I can't stay focused on something I want to get done, I keep reflexively opening web pages when I get stuck or bored with it. I'm not really experiencing the 'quiet thoughts' I thought I would. How long did it take for you to feel correct on Adderall and did you have to increase or decrease your dose?