Yes, there is! Tunaisafish made a rather nice package of files to deal with enthusiasm and enthusiasm decay to make more sense.
You can find his Enthusiasm Overhaul package
here. The descriptions are very clear along with instructions to use the files contained within the package.
Hope this helps you. I personally use the Enthusiasm Overhaul package myself and had no issues with it. My latest EP is Mansion&Garden, so it will work upwards to that EP if you have FreeTime installed too.
