Whats the hardest job when you are restoring a car

FINISHING IT!!! getting to a point where nothing else needs to be done beside wiping and waxing and such......... I "finished" my Bonneville in 2003 and I am still tweeking it....I "finished" my 66 Cuda in late November of 2010 and I still tweeking it........ which leads me to believe the HARDEST JOB is to know when you are DONE, as in DONE DONE, good to go, migration to maintenance mode...... somehow that seems to be the HARDEST POINT TO REACH!!!