If you want insight into how Jupiter in Gemini will affect you, look back 12 years at what happened last time. This will give you a general flavor of the transit but there is a lot more that you can glean.
Seeds are planted during Jupiter transits. Twelve years later you can see how those seeds developed, if they developed. Jupiter rules journeys and this is another way to look at this. What journey did you begin in the latter part of 2000 through mid 2001?
Twelve years ago, I started writing (Gemini) and more specifically, storytelling (Jupiter) during this transit. I started on a message board (how Gemini) at the end of 2000. I started publishing (Jupiter) to a blog in 2001. The transit took place in my 5th house (creativity) so this was textbook for the transit.
We took some of those stories and made them into a book, when Saturn came along. I wonder if at the end of this 12 year cycle, those stories get published.
What happened in your life, the last time Jupiter was in Gemini?