you know you´ve played too much Lfs when: you are in road, you see some nice place without any house or anything on it, just trees, and you start thinking on make a real Blackwood circuit on it (xD).
you know you´ve played too much Lfs when: you try to look for the Shift+a combo when you want make your IRL car sound better.
you know you´ve played too much Lfs when: you look in the Oil pressure gauge thinking that it will show your fps.
I used to do that... i actually found, with some testing, that walking sideways sometimes decreases the times it takes from the computer to the bathroom and other parts of the house.
Maybe testing stupid things racing related is an effect?
when the guests join your birthday party and you ask them "do you see something changed?" - "you got a new rubber dolly?" - "that, and just for this party, i UNPLUGGED MY WHEEL!!!"