Being tired means you worked hard and is fine, being sore doesn't have any causative relationship with getting stronger and pain is nothing to strive for . The notion that overstressing a muscle to the point muscle cells are damaged is necessary to spur muscle growth has been thoroughly debunked, and was a classic case of correlation not equaling causation. People who work hard to develop muscle often overdo it a bit so you'll see both muscle destruction and development at the same time, but one isn't necessary for the other.

As I said above, I don't think there's going to be any problem with the OP increasing to 30 mile rides (and beyond) in the near future, but the idea that no significant development is going to happen until the OP makes himself miserable and sore is nonsense.