I love travelling solo- it's great for people-watching, and (depending on how outgoing you are, and languages obviously help too) you have more chances to get to know locals (normally I am not that interested in meeting other tourists- kind of misses the point).

For eating solo in PRG, try going to a pub, where the service is informal and where many people will only be drinking. The food won't be exquisite, but Czech cuisine is reasonably basic anyway...which is a good thing, because it's easy to get it right.