People have many different social connections through family, friends, and work. They might not realize just how many people they have met until they run into someone on their own. This person might not have been someone that attracted them when in the company of family or friends, but they might find they are on a surprise date when they meet in a different venue. It could be the date of a lifetime that will lead to a relationship, or it could turn out to be a nice time with someone new who can turn into a friend.
Meeting someone in different circumstances often changes the emotional atmosphere between two people, and they might feel a sense of freedom that was not present when they first met. If they were at work, there might have been the feeling that they should act properly in front of their co-workers. Asking the other person out on a date might have seemed too risky, but meeting them at a local coffee shop by accident could be just the impetus needed to overcome those feelings of impropriety.
Families often introduce their single members to someone new, but being pushed to go out with a stranger can be uncomfortable. They might not know each other at all, so even a query about a date could be taken in the wrong manner. These two people might never go on a date unless they run into each other while shopping or running errands, and their entire social connection could change when they find out they prefer the same shops.
Making a dating connection with another person is about having something in common, and the social setting could be a negative when two people meet. If they later run into each other, they could be more comfortable because they realize there are things that can bind them together. This is when the opportunity for a surprise date can occur.