Quicksort is usually randomized. So it is not a matter of the order of the elements, it is a matter of very bad luck on selecting your pivots. So even if worst case performance is very bad it is very unlikely. But you have to understand why.

You probably will never implement quicksort, but it is useful to know, how it works, as you may be able to use some of the ideas on your own algorithms. Quicksort is also beautiful, so it can be a good inspiration on writing good software.