Ruling both Sagittarius and the 9th House in astrology, you might imagine Jupiter is a bit of a flaky, pretentious douche. It’s also exalted in Cancer, so you might want to add emotional to the list. So, imagine Jupiter, sitting there, weeping as it tries to explain existentialism to you but then, deciding you’re too stupid to understand and wandering off.
Jupiter’s retrograde transit happens right around every 13 months. It will have about 3 months leading up to the retrograde station itself- known colloquially as the “Shadow”. Then, it stations retrograde for about 4 months, 2 days. After that, 3 months of still feeling the impact a bit here and there. Those times before and after are actually when the planet is “stationing”. That is, it's “going in” and “going out” of retrograde station itself.
To guild the turd a bit, it shows you where your excess and greed might be a little out of control. It can also illuminate those areas where you’re a bit less the doer than you ought to be. That said, it will also point out where you have been leaping before you look. It does so by stalling out some awesome shit you were working on, or having it implode in your face. In respect to “a little out of control”, you get to see how your delivery habit has over drafted the crap out of you. Things like that. Like all retrograde cycles, this is cast as “external challenges to help aid in beautiful opportunities for inner growth” which, when translated: you’re going to find out where you need to get your shit together. Where excess might be an issue or what you might be doing that completely derailed your start up, project, budget or whatever. As in, everything expansive blows up in your face or absolutely crawls and hits a wall.
This gives you the opportunity to reflect on quite a bit, but may also lead to some unhealthy coping mechanisms.