I don't always have to be doing something. But I do need to have some project going. If I have some longish term project (take 3 months to a year) with a clearly defined end to the project (not a date but a definitive end mark such as something I want to have built or special activity I want to be able to do) to work on I find it easier to relax. Even if I'm not working very fast on my project just knowing I have one and am slowly working on it makes me feel better. Like ok, right now I'm just vegging out in front of the TV, but I have a plan and a goal and I did something towards it this week so I'm not being useless, I'm just working towards something at my own pace. Like when I was young the goal was learn enough English that I could read in my computer magazines whether a game was good or bad and why.
I find it really hard to do things that don't have clearly defined goals, and others seem to have a hard time understanding that. People sometimes tell me I should exercise, yet they don't grasp that that's a goal that's too vague. If the goal was 'improve physical stamina to where you can walk x miles within y hours without getting winded and climb z with ease' for the purpose of 'taking a special trip and climbing mountain a' I could understand the project. 'to get into shape' is too vague a goal. It's like saying 'you should make yourself more happier', leaving aside poor grammar, it's a goal that has such poor definition I wouldn't even know where to begin. It also has no clearly defined end purpose other than the project itself.
It's frustrating because I try to explain that my mind doesn't work like that and people don't even care to understand it, they just tell me I need to try harder to think in a way that's alien to me and leaves me confused, adrift and with growing anxiety. When I have no project I do get restless, more prone to depression and I start to forget things because nothing's sticking in my mind. There's no anchor to fix me to one place, so I drift.