Believe it or not, it might be.. biological.
Humans have moments of peak awareness, tuned to the height the sun is in the sky - that is, according to one's internal clock.
Just as its not a good idea to go for a competitive drive just after lunch (youll get that after-lunch-sleepiness), there are other times in the day when your reflexes and coordination are at an all-time high.
If you are aware of it, you'll find some times of day when you seem to always do better, react faster and more accurately.
Of course, this is just a "modifier" - then main problem usually is lack of concentration, lack of caffeine, etc... all of the above, really.
Another advice is: Warm-up. do something that will pump your reflexes up. Like go play some hyperfast shooter for a few mins before going to LFS (something like Quake3 - where you dont get the option to slow down for a moment). When you get to LFS, youll be so used to having to think uber-fast, it will seem sloooow.
OR drive in LFS a car thats a lot faster than the one you are gonna go drive in - to get ready to drive the FOX, I usually do the same combo in the FO8/BF1 -then driving the fox feels like driving in slo-mo