When Arrow began, the series was unique i that it had the two narratives going regularly, the now and the flashback. We've known since the debut that Oliver Queen was away from Starling City for five years. And we knew that some of that time away involved the Bratva (Russian mob) and learning the Russian language. The show runners spoke at the Writer's Guild Festival on Saturday about the Flashbacks, how they seem to have diminished quite a bit this season and what's up with season five.

Part of the appeal of the flashbacks – certainly in the first two years, but I think the first three years – is seeing what a big difference Arrowit is between Oliver Queen in the present day and Oliver Queen five years ago," EP Marc Guggenheim shared. "The problem is that we are telling a five-year story in the flashbacks of Oliver becoming the guy you met in the pilot. So the deeper you get into the flashbacks, the closer he becomes to being that guy, and, thus, you lose that element of the flashbacks that was so interesting, which is how different he was…. That's something we have struggled with this year.

Moving forward to season five, Wendy Mericle had this to say:

We know what we're working up to. The season will be easier to break because we have an endpoint, and we work backwards from there. I don't want to tip too much, but it's a very good possibility that we'll finally find out how Oliver got that Bratva tattoo and how he learned to speak Russian.

[Source: TV Line]