Highlander Alistair McLeish, who was a member of the 4th Battalion, the Royal Regiment of Scotland, was found dead in his room at the Bourlon Barracks in Catterick Garrison, North Yorkshire, in July last year.
An inquest heard today how the 18-year-old had "appeared to be a happy, normal guy" who was enjoying his service and seemed to be performing well, with superiors singling him out as an example to other soldiers.
But he was found hanged in his bathroom on July 3 last year, with a coroner at Harrogate Justice Centre being told he was nearly three times the drink-drive limit at the time.
The teenager's mother, Karen McLeish, said in a statement that was read in court: "We are totally distraught as a family about Alistair's death, and cannot come to any logical conclusion as to why he would take his own life.
"It is a complete shock to all of us."
She said her son had long held aspirations to join the Army and follow in the footsteps of his father and grandfather, both of whom had served, and had trained at the Army Foundation College in Harrogate.
Mrs McLeish said he "appeared to love" his role in Catterick, having arrived there at the end of 2017.
The court heard how Highlander Dylan Rollo, who was also living at Bourlon Barracks, had known the teenager for around eight months prior to his death.
In his statement, Highlander Rollo said his friend had "appeared to be a happy, normal guy who was one of the lads", adding that he had not seen any evidence of deeper mental health issues.
He said that on the afternoon of July 1 last year they had been socialising together, with Highlander McLeish drinking two bottles of Buckfast.
When the 18-year-old was found dead, a third bottle of the drink was found by his bedside, with forensic toxicologist Nigel Brown revealing his blood alcohol level post-death was 220 milligrams per 100 millilitres, the legal drink-drive limit being 80 milligrams per 100 millilitres.
The court was told that Highlander McLeish had been given July 2 off work as he had recently returned from a 10-day trip to Paderborn in Germany.
The coroner heard that his movements between leaving Highlander Rollo on the evening of July 1 and being found dead more than a day later were still unknown, with colleagues wrongly assuming he had gone home to Selkirk in the Scottish Borders.
Major Frederick Macnair, who was in charge of Highlander McLeish, said he had seen him on a day-to-day basis since the end of 2017, describing him as a "big character".
He told the court: "I had made a point of singling him out in front of his colleagues and saying to everyone that this is how they should behave, and that this was the example they should follow."
Addressing the teenager's parents, Coroner Rob Turnbull, who made a ruling of suicide, said: "You said he loved the Army, and from what I have heard there is not reason to suggest otherwise.
"It is not my job to ascertain the motive, but I am guessing you would like very much to know.
"Whether he had been ruminating on things is not known, but there is no apparent motive for this tragic incident."