Matty, younger brother of Sean, made his senior bow during the Magpies' Premier League Asia Trophy campaign in China last summer, with the 19-year-old impressing under new head coach Steve Bruce before netting his first goal in a 2-1 friendly win over AS Saint-Étienne at St. James' Park.
The midfielder, who made his full competitive debut during United's Carabao Cup defeat to Leicester City at St. James' Park, reminisced on his first days at the Academy and his dedication to making the leap from youth to senior level.
Speaking at Newcastle's Little Benton Academy, Longstaff said: "When you go up there (to the first team), you've got to try and see the level they are playing at. When you come back down (to the Academy), you have to try and find those ways of getting to that level.
"I remember coming (to the Academy) on a trial when I was younger and doing well enough to get signed. When you're younger, it's great and then you progress through all the year groups.
"Coming in on day release, you have people such as George Scott (Welfare, Education and Safeguarding Officer) who look after you, and that's when you start to see when you're in full time. You're training twice a day and then obviously you get up to the top end and it goes from one thing to another.
"This pre-season, I went to China and that's when the gaffer (Steve Bruce) first saw me. The biggest thing for me was trying to work hard and stay around for as long as possible. Luckily, I'm still here at the moment.
"You've just got to keep doing the right things all the time when you're down here and keep working hard to get you the chance up there. That's the biggest thing."
Whilst completing his transition into Newcastle's senior squad, Longstaff believed the strong support shown from older brother Sean as well as his dad, David, highly benefited the youngster.
Longstaff has travelled with the first team to Norwich City and Tottenham Hotspur in recent weeks but didn't make the bench on either occasion.
He said: "I think having Sean there helps a lot with being a bit younger and having someone to lean on. He probably doesn't know it as much but when you have someone that you know very well, it makes it a lot easier making the next step up knowing there is always somebody there to speak to.
"My dad has also been a pretty big influence. He's at every game, travels everywhere and is always there to tell us 'well done' but is also there to tell us, from being young, when we haven't been good enough and what we need to do. Having him around keeps you in check and makes sure you are doing the right things."
