[valarauca1]

Geo-tagging.

If you both updated your status, or used facebook messenger from the same location multiple times. Facebook assumes you either met, or know each other. Since you attend the same place at the same time.

Stuff like this is why I deleted facebook. If I wanted to know these people I would add these people, I don't need suggests based on literally spying on my day to day activities.

[talltofu]

I replied earlier - but no, that's not a possible answer. There are close to 100 kids there at the same time. So about 100 parents checking Facebook at the same time. Why only him? Also, both of us are in the pool with our kids (parent-toddler sessions), so no Facebook for us