The war-ravaged country became the 12th test playing nation when they took on top-ranked India in the one-off match at Bengaluru's M Chinnaswamy Stadium amid much fanfare this week.
However, it proved a sobering experience as India, shorn of key players and regular skipper Virat Kohli, first forced Afghanistan to follow-on before dismissing them twice in as many sessions for their biggest test victory inside two days.
"The learning curve is huge," former West Indies player Simmons said after his team were thrashed by an innings and 262 runs in a total mismatch.
"It's a mountain to climb. But I do believe they want to succeed, they want to be good at it and they work very hard.
"We now know that we have to work five times as hard as we worked in the last four weeks. I believe that they will get there."
Afghanistan can contend well in limited-overs cricket, something they proved with a 3-0 blanking of Bangladesh in a Twenty20 series preceding the Bengaluru match, but were unable to cope with the demands of test cricket on their debut.
"I will blame about 30 percent on the occasion and I'll blame a lot more on the naivety of what test cricket is about," Simmons explained.
"You can play as much Intercontinental Cup and four-day cricket as you want but when you get upstairs to the big league, especially against the number one team in the world, it shows. And ... it showed in a big way."
The Indian cricket board (BCCI) has provided Afghanistan with two venues -- in Greater Noida and Dehradun -- to stage their 'home' matches.
To help them get more exposure, the BCCI has also decided that Afghanistan will also get to play a practice match against teams visiting India.
"There has to be a lot more 'A' team cricket played against big countries' 'A' teams... like England, India, Bangladesh, Australia like that," Simmons said.
"That's the best way for us to close this gap on a quicker term."
First Published: June 16, 2018, 1:57 PM IST