I imagined like someone directing an orchestra, so I translated: "when I direct, I think". I suppose then, that if I only use the verb "dirigir" alone it would be related to driving and if I want to say that I direct something I have to complete the sentence, like "eu dirijo uma orquestra". Am I right?
No. It's a factual assertion (I think when I'm driving). That unsure "I think" takes the verb "achar" - "acho".
- Quando você se lembrou do código? Quando estava dirigindo... acho.
In any case, it would be weird to use it like that when the action is the present (just like your examples in the past show).