The heat goes into whatever the group is trying to do
Everything expansive in you gets spent on collective things. Mars in Sagittarius in the 11th house sends your force into causes, communities and friendship, so the group acquires momentum and a set of ambitions considerably larger than it had before you arrived.
The sign is why the contribution is belief rather than administration and the house is why it lands on collectives. That makes you the person who convinces a circle that something is possible, and rarely the person still present for the part where it has to be maintained.
A circle with no postcode in common
Your circle is scattered geographically and socially, assembled out of people you met while doing something rather than people who happened to live nearby. It is a genuinely interesting set and it requires actual effort to stay in contact with any of it, since nothing about proximity is doing the work for you. Put three of them in the calendar with dates on rather than trusting the next coincidence to arrange itself.
Joined at full commitment, outgrown by year four
You enter a group completely, contribute enormously, and then at the point where the interesting decisions are finished and what remains is maintenance, your attendance quietly falls away without any announcement. It is not disloyalty and from inside the group it is indistinguishable from it. Say plainly that you are stepping back and why, rather than allowing the attendance to taper. The fading is the part people remember and it is the only part that was avoidable.
The cause you would rearrange your life around
When something genuinely matters to you the commitment is total: the time, the money, the move if necessary. That capacity is unusual and it is what makes you worth having. Concentrate it on one thing per season rather than three, because spread out it exhausts you across a wider front and changes nothing.
Arguing about the future is not building one
Your circles produce excellent conversations about how things should be, at length and with real energy, and the conversation is satisfying enough to substitute for the doing. Once a year take one of them and give it a name, a date and a person responsible. The talking is genuinely useful; nothing in it stops on its own.
The circle exists because you kept insisting
Groups in your life form around an idea you would not let go of, and several of the people in them had no interest at the outset. Your persistence is the whole reason any of it exists. What that also means is that the thing has no independent momentum, so it stops when you do. Give two other people a genuine stake in it, including the right to change it in ways you would not have chosen.
Word reaches you from the edge of the map
The useful information in your working life has consistently come from the outermost people you know rather than from anybody close, because that is where anything unfamiliar lives. Treat the loose edges as the asset they are: an occasional message to somebody you have not spoken to in three years, with a specific line about what you are looking for. Vagueness is why those conversations have historically produced nothing.
Staying for the maintenance phase
Everything collective you have started needed a dull second stage from you and mostly did not get it, which is why several good things in your history exist only as beginnings. Pick one and stay through the boring part, once, deliberately. What is available on the other side is not obtainable at the founding, and you have never seen it.
Met through something you were both doing
Relationships in your life tend to begin inside an activity, a trip or a cause, which gives them momentum and a shared context from the start. It also means the bond and the activity can end together. Build something between the two of you that has nothing to do with how you met, early, while there is no need for it.
Anything with a team survives the flat months
Solo effort lapses in you the moment the goal loses its shine, and anything with other people expecting you persists through the same stretch. That is worth building on rather than resisting. Join the club rather than buying the equipment, and the flat periods stop being the point at which everything stops.