Mercedes team boss Ross Brawn had said before the Sakhir event that if his outfit performed well in Bahrain then it would be quick everywhere because it was a track where it had struggled in 2012.
But although Nico Rosberg took pole position, he and Hamilton were beset by tyre overheating issues throughout the weekend and found themselves unable to challenge for a podium.
Their plight has highlighted the work Mercedes still needs to do before it can regularly challenge at the front, but Hamilton says he is not leaving Bahrain feeling downbeat.
When asked by AUTOSPORT if the tyre struggles were evidence the team could face similar difficulties to those of last year, Hamilton said: "We had a long meeting about that.
"We got a lot of information from these first four races to know that going to a cooler Europe will be good for us.
"It is good to get one of the most difficult races of the year out of the way in terms of heat, but there are a lot of areas that we need to improve on.
"To get fifth, two thirds and a fifth [in the first four races], though, I could not be happier.
"When I decided to join the team I knew potentially it could be a lot worse than that."
Even though the Bahrain weekend did not suggest that Mercedes' rear tyre issues are a thing of the past, Hamilton does not think its plight is a cause for concern.
"Mercedes never was quick here," he said. "Last year Red Bull won here and they have been strong for the last three years I am pretty sure, so that is not a real surprise.
"I don't think it will be like that in all the races. Red Bull have struggled in qualifying at some races, and when we get to the cool places maybe we will be closer."
Although Hamilton missed out on achieving his third consecutive podium finish, he says considering the gearbox change and early race form, ending up fifth at the chequered flag was a tremendous achievement.
"It was a massive positive, that race," said Hamilton. "I am very happy with it.
"Fifth was the best we were hoping to get, and obviously after the first half of the race which was a disaster for me, I kept thinking that even that would not be possible.
"So, after falling back so far, I feel great."