Ty for adding that context. I thought most people would know part of the peace treaty meant that FARC became a political party and has secure seats in congress (which makes all the worst people in Colombia mad AF), when it's really not common knowledge. They seem to be doing well, although it's really hard to build political power when the bourgeois media has done nothing but demonize you and your name for 60 years. If anything it shows how attached they are to the FARC name. It should be said that many former FARC fighters (especially the lower-ranked ones) chose to step away from the party, and just returned home to aid in the development of the rural communities where most of the fighting used to happen (and still does sometimes), alongside some of the victims of the conflict, who have also returned home.
I have my criticisms of FARC while they were in armed struggle, but they seem to be committed to the truth and reconciliation process, so I'm willing to eat my words if they turn out to be decent people and see it through the end.
As you said, Petro was a member of a different, much shorter lived guerrilla group. M-19 seemed to be one of the more ideologically uncompromising guerrillas, and one of the more urban ones, too, with a lot of its activity in cities and its founders being graduates from public universities. They negotiated with the government in the late 80s, and entered political life just in time to be a key part in drafting the 1991 Colombian constitution, which, as liberal as it is, is a beautiful document that even radical leftist Colombians recognize as an achievement in enshrining the ethnic and cultural diversity of the country as a legal fact, and guaranteeing the rights of so many vulnerable Colombians.
It goes further back. Coffee houses in Britain were a huge thing in the 1700s, where a lot of capitalist theory and practice was created.