It was an hour-long meeting that prompted a change in attitude, body language and energy over the five days at the P Sara Oval. The meeting was an effort to trigger introspection after the 259-run defeat in Galle, and the disappointments of the first three months of 2017.

Coming into this Test, early 2017 had been an extension of the heartbreaks of 2016 for Bangladesh. Close calls had left them with nothing, most infamously in Bangalore last year, where they conjured up a way to lose the World T20 game against India. At home a few months later, they gave away winning positions to Afghanistan and England, and then did the same in New Zealand.

In Wellington and Hyderabad, they had a chance to draw Tests against New Zealand and India in away Tests - a difficult enough task for many established teams. But here were Bangladesh poised for such a result. They couldn't finish the job, though, which prompted many to question their stomach for a fight. In Galle, they reached a nadir, bowled out for 197 on the last day and that too quite meekly.

After that game, having moved to Colombo, they sat in their dressing room on one of the training days at the P Sara Oval and spoke to each other, frankly, taking their own sweet time. Chandika Hathurusingha, Tamim Iqbal and later Mushfiqur Rahim explained later that this was a session they needed to recover from the Galle defeat.

Coach Hathurusingha said change came in response to questions he asked the players. "They decided they needed to change," Hathurusingha said. "I prompted the questions and then they had a heart-to-heart conversation in the dressing room for nearly one hour. The positive thing we saw here was their energy over the five days. We still have some areas to improve, but there's vast difference in body language and effort in this game."

Some might be reminded of the meeting India had during the 2003 World Cup, after the crushing defeat to Australia early in the tournament. As per the book of their then coach, John Wright, Indian Summers, they introspected and decided that Sourav Ganguly will bat lower down while Sachin Tendulkar and Virender Sehwag opened. After that, they came out with a changed approach, and marched into the tournament's final with a string of victories.

Bangladesh, Mushfiqur said, spoke to each other about the value of doing small things right in a game, the small things that could come back to hurt a team later. Such closed-door meetings had happened in 2012, when the team made the final of the Asia Cup, and in 2015, when they stormed into the World Cup quarter-final. It didn't take long for results to show then. It didn't take long for results to show now.

Bangladesh emerged from Wellington and Hyderabad with plenty of lessons, but they needed a win to tell the world that it was not mere show. They needed to show they had substance, and this win has done that.

"We tried to understand the value of a run, a misfield," Mushfiqur said. "Giving away runs in the first innings may not seem much at the time, but it comes back to hurt you at the end of the day. We tried to recognise these small things. The fact that we absorbed each and every bit of it was quite impressive; the batsmen and bowlers played with responsibility here, which made me happy."

In Wellington and Hyderabad, Bangladesh's bowling proved to be their weakness as they failed to have an impact on the New Zealand and India line-ups. They had a very inexperienced attack - as is often the case for Bangladesh on tours - but with Courtney Walsh in charge, there was hope that it would learn to be more intelligent in its bowling.

Mustafizur's performance was outstanding in this game but it was Subashis Roy, a left-field choice ahead of Kamrul Islam Rabbi, Rubel Hossain and Taskin Ahmed, who provided steadiness from the other end. The spin attack too was efficient and though Taijul Islam was underused in the second innings, Shakib Al Hasan and Mehedi Hasan kept their ends tight when nothing else was happening.

Hathurusingha said that Mustafizur's spell on the fourth afternoon turned the game in Bangladesh's favour, at a time when nothing was going the visitors' way. He said that a bit of troubleshooting with Shakib also helped his bowling in this game. Shakib took four wickets in the second innings, while Mustafizur picked up three.

"The game changed through Mustafizur's spell after lunch on the fourth day. Nothing was happening, [and it was] very hot for the fast bowlers. He came and bowled a magnificent seven-over spell to take three wickets," Hathurusingha said. "It was a crucial time of the game for me.

"I had seen [Shakib] bowling against South Africa in 2010 or 2011. He was a different bowler here, and he showed it to me. We had a very good discussion on what he is not doing now. We discussed after seeing video footage. He bowled very well in this game. When Fizz [Mustafizur] was bowling from one end, [Shakib] checked the runs from the far end."

Bangladesh have now tasted a hard-fought away Test win. They emerged from Wellington and Hyderabad with plenty of lessons, and have had impressive individual performances in Tests of late, but they needed a win to tell the world that it was not all mere show. They needed to show they had substance, and the P Sara Oval win has done that.

One meeting perhaps tweaked their mindset. Now, they have to keep reminding themselves of the small lessons they picked up in this game too. Maybe, ahead of their next Test, they can sit down again and remind themselves just how much they can still improve. Only then can they really succeed in the place they have always wanted to: Test cricket.

Mohammad Isam is ESPNcricinfo's Bangladesh correspondent. @isam84