Rented a house with friends in sf in 2016. We created a facebook group for our neighborhood, put up signs, and very quickly had a similar experience. A few neighbors over for drinks one night, hosted a weekend bbq a few weeks later. Quickly got to know a lot of people on my immediate block. One guy fixed my bike. An older woman called me when her fire alarm was intermittently beepting, to see if I could fix it. Had a few other events through the group, they were a highlight of the year. Made it clear to me how much latent desire there is for connection / friends from your neighbors.