"When You And I Were Young, Maggie" is a kind of sentimental song for the lost youth and fear of aging.  It is performed by Foster and Allen, a musical duo from Ireland, consisting of Mick Foster and Tony Allen. While they are singing, Foster plays accordion and Allen plays guitar.

According to Wikipedia, Canadian school teacher George Johnson from Hamilton, Ontario wrote the poem "When You And I Were Young, Maggie". It was published in 1864 in a collection of his poems entitled Maple Leaves.

Margaret "Maggie" Clark was George's student. George and Maggie fell in love. Maggie was in poor health. One day, George walked to the edge of the Niagara escarpment, overlooking what is now downtown Hamilton, and composed the poem.  George and Maggie  were married in 1864 but Maggie's health deteriorated and she died a year later.

James Butterfield set the poem to music and it became popular all over the world. Johnson died in 1917. The schoolhouse where the two lovers met still stands on the escarpment above Hamilton, and a plaque bearing the name of the song has been erected in front of the old building.