'Keep smiling' was a popular expression of the time, a cheerful, stoic phrase in response to any eventuality - including in this instance the death of your son. But to be positive, not to allow pessimism to creep into your thinking was instilled into the British public during the war. It was an attitude summed up in the chorus to a popular marching song written in 1915 by George Henry Powell and set to music by his brother, Felix.

Pack up your troubles in your old kit bag,
And smile, smile, smile,
While you've a lucifer to light your fag,
Smile, boys, that's the style.
What's the use of worrying?
It never was worthwhile, so
Pack up your troubles in your old kit bag,
And smile, smile, smile.

Robert James Price's service file still exists and it shows how valuable it would have been if so many hadn't been destroyed in the blitz. It's not that Price's file says anything special but that there is so much detail in it.
Price, an assistant to a wholesale cigar merchant in 1911, was a territorial in the 7th Battalion the Middlesex Regiment. He reported for duty on 6 August and on 3 September went to Gibraltar. The battalion remained there until 14 February 1915 when it returned home and after a month in England went to France.
On the 28 August 1915 Price was wounded in action - with gun shot or shrapnel wounds and a compound fracture of his left thigh and right knee. He was treated first at a Field Ambulance 'in the field'. On the same day he was admitted to No 7 Casualty Clearing Station at Merville and transferred the next day to No 5 Stationary Hospital, Dieppe. He died there six days later.
In January 1916 the army returned his personal effects: pockets case and photographs, post cards, pipe and lighter (broken), book and pencil, dictionary, belt.
Price was the only son of Frank and Sarah Ann Price of Southend on Sea. His parents had two daughters: Gertrude Sarah and Margery Sarah. Gertrude died in Rochford Essex in December 1917. I haven't been able to find out the cause of her death.