I bumped into folks coincidentally on 3 separate occasions today.

Encounter #1: Exiting the lift at my vendor's office building while a friend was stepping into it.
Surprise element: Medium cos a) I'm seldom at my vendor's site, b) it only takes a few seconds to miss someone in the lift.
Result: Caught up with him before he went on vacation.

Encounter #2: Meeting a business associate in the parking lot at my vendor's office building.
Surprise element: Low cos a) I don't really know him, b) the whole world seems to have the same vendor as us.
Result: Gained a business lead from him. Yes, you can find business in a parking lot. Go figure.

Encounter #3: Meeting a junior college schoolmate across the road from my office building.
Surprise element: High cos a) he still remembered my name though I haven't seen him for many years, b) it turned out he's working in the next building to mine for the past 1.5 years and we never realised it.
Result: Got someone new to go lunch with.

Not a bad day really.