This is applicable in all areas. I’ll talk specifically in the interview context as I’ve been on both sides of the table for a significant amount of time.
Luck can manifest in a lot of ways. Here’s an example:
There are internal deadlines in companies to close a position.
Now you don’t know whether you’re an early applicant or very close to the deadline. In the former case, they have more time to close this position so interviews might be a bit harder. Extending this, interviews might be a little easier in the latter scenario.
You never know when lady luck is on your side, so focus on your efforts and keep taking shots. Don’t let one interview define you.