With the exception of the giant pilot watches worn in unpressurized bombers in WW2, or the equally oversized dive watches of the same era, normal watches were in the 33mm and 34mm size. The Rolex Explorer was offered in both 34 and 36 sizes. Omega in the 30s and 40s made some nice 38mm dress watches...but that was not the norm.
Beginning in the late 80s with the Brietling watches...bigger became...bigger. Part of it was the retro pilot looks, a lot of it was "mine is bigger than yours" stuff. It's been going that way since. However in the last few years there has been a renewed interest in something that is classier and more useful...the 34 and 36 size of watches. Even slim movements are gaining interest from buyers.
Your 34mm is just perfect. It will always be a classic watch...and it will be more useful and comfortable than the "big" watches. That said, the 36mm DateJust is far from big by today's standards and you may want to try one of those eventually...but don't make those 2mm difference stop you from enjoying your 34mm Rolex.