There was a time when Ange Postecoglou had to remind people about his achievements.It seems no one will need any more hints after Postecoglou became the most successful coach in Australian domestic soccer history on Sunday.But just where Postecoglou will add another chapter to his success story remains anyone's guess - including, he says, the man himself.Linked to a lucrative deal at Melbourne Victory, Postecoglou looked to have received a fitting farewell at Brisbane Roar after they downed Perth Glory 2-1 at a packed Suncorp Stadium to become the first team to clinch back-to-back A-League titles.He now boasts four national titles from as many grand finals, including two with South Melbourne in the old NSL in the late 1990s.The stage was set for Postecoglou to make a triumphant sign-off - but even he did not know what his next move was.And it seems he wouldn't have it any other way."If I am saying it is difficult (to leave the Roar), then the decision has been reached," he said."But from my point of view I am proud of the work we have done here."Once I complete the celebrations of this one, I will see what my next challenge is."It is part of my nature that I am always looking to see what I can do next - that restlessness I guess is what is causing the uncertainty at the moment."But that is just the way I am."Postecoglou was a solid defender who earned four Socceroo caps and two national soccer titles - along with 193 appearances - with South Melbourne.But as a coach Postecoglou has reached rarified air."I feel a bit silly because I keep bringing it up, but I just feel people have forgotten (about his coaching record)," Postecoglou said."It's what drives me as a coach - I am constantly trying to seek some credibility and leaving my mark."Four (titles) is great - I am really proud of that. It is almost overwhelming."When I started, I had some real ambition to do things that I hoped were great - I think I have made a little bit of a mark now which is great."Asked point blank whether he was leaving for the Victory, Postecoglou said: "I am going to enjoy the moment."I think I deserve to bask in the celebrations in the next couple of days."When the time is right and I sit down and talk to the relevant people, the next move will be decided."I can understand the curiosity."(But) I haven't entertained any other thought but to coach this team to another championship - I think I deserve a day to enjoy that."