I was about to answer "a lot," but I guess it truly depends on where I am in a story and how I'm feeling about the tale at that moment. There are times when I am obsessed by the characters, the world, the plot, and I have a hard time concentrating on anything else. This state just comes upon me, but it is more easily reached when I've been writing consistently.
Sometimes, though, I do my daily writing, but my my mind is not obsessed with what I'm doing. I'd consider that I'm a healthier individual while in this state (because I am more open to and concerned about others--it is easier to have a conversation with me, frex), but I don't like it. In fact, I feel there is something wrong with me and wish the random ideas and snippets were more present.
Then there are times that I have to literally say to myself, "Ok, you have this problem; think about it." And from there I tackle it.
I guess, though, my response could have honestly remained "a lot;" even when I'm not actively writing, I'm thinking that either I should be or I would like to be.
As of the IRL part of this question....hmmm, I would say that I'm more influenced by things in real life that find their way into my fiction and my characters' lives.