Hmm... let's see...
a) Everything is "take one". Usually, there's no chance to do a take two because there are time limits and of course, it's a once-in-a-lifetime affair. A bungled thing is a bungled thing is a bungled thing... Get it?
Oh, and it's not easy for couples to move on when there are too many bungled parts... Wrong music playing at the first dance, forgotten distribution of gifts to principal sponsors, etc.
b) Your "officemates" are constantly changing. While there are times when suppliers get lucky and end up working with people they are used to, there are also days when their co-suppliers are downright difficult to work with or are nice but inefficient. When that happens, suppliers who know better need to go beyond what they are expected to do -- just to save the day, literally and figuratively.
So yes, I am personally thankful to all my couples who got reliable suppliers. No added stress... yey! :)
c) You need to be healthy all the time -- first, because the couple did book you and they wish to see you on their big day and second, because it's not easy to look for a replacement. So as the saying goes, "the show must go on" (even if you have fever, you're coughing your lungs out, etc.)
Why am I writing this? Well, I've heard too often from outsiders that it's easy and glamorous to be in the industry. While the job can be considered glamorous from a certain vantage point -- "easy" is far from the real picture. It's as difficult a job as any -- we don't have lots of room for mistakes, in fact, even just one mistake can prove "fatal" to our reputations; we don't have emergency leaves and the like, and most of all, we work in a constantly changing environment where we must learn to adapt really quickly, step up and go beyond what is required of us, and deal with personality quirks on the side -- all in the name of giving the couple their dream wedding.