I don't believe that luck is anything other than chance. It's like playing backgammon - you can get yourself into a position where almost every combination the dice fall in is positive, but you can never actually control how the dice are going to fall.
I was walking home from Liverpool Street station the other evening, and literally every crossing I changed to show a green man just as I walked up to it. Every single one. A bit like that annoying advert with James Corden, except I didn't ask anyone to "just call me Mr Green Light".
It wasn't my only stroke of luck during the day. Earlier in the day, I'd been giving a serious announcement to my team in the office. All standing around in a circle in the break-out space in the office, it was after I'd finished speaking the MD was talking that I realised that my phone wasn't on silent, that I was expecting a call and that my ringtone is currently the theme music from Strictly, starting with a bit "Hoooooooo!" noise at the beginning. Even though the MD was talking, my attention was actually on my phone rather than her, willing it not to ring right at that moment. Fortunately, it didn't.
Good luck must run out eventually. Or more precisely, the random order in which good and bad things happen means that every run of good things is only going to be finite in length. Like tossing a coin - every run of heads is going to be broken at some point.
I feel like there should be some metaphor here. There isn't. I was just struck by how many green lights I saw on the walk home the other evening. Nothing more.