I love my job - but the nature of full-time paid Christian ministry is that there's rarely anything that you can start and finish on the same day, and see some effect of the hard work you've put in. It's rare that you get to a point where there's nothing else that you can do for a particular person or project. Additionally, the times where you can finish something as a job well done are few and far between - and, of course, it's only eternity where the fruits of our labours will be seen.
For these reasons, and for a change, I find it quite therapeutic to be able to do something practical, where a difference can be seen. It's nice to have that feeling of satisfaction, whilst at the same time being reminded that giving oneself fully to the work of the Lord will never lead labour in the Lord in vain.