"It is a great challenge in the Premier League and taking over a big club that didn't have a great year last year, you understand it is not going to run smoothly," Postecoglou said.
"I have enjoyed the whole season. I have got some lofty ambitions for the football club and until we reach that point I am not going to be smiling too much.
"I have enjoyed it and looking forward to pushing on from here.
"I am obviously not delighted with the way we finished the season but in fairness to the players and staff we have been in the top five all season, in a year where there was a fair bit of upheaval.
"We finished eighth last year, player turnover, different football, different way of training, it is not easy to maintain a level when you are trying to do that.
"Even in our tough periods this year we have still been competitive for the most part. I think I have got maximum effort, which is all a manager can ask for."