"I worked as a labourer. I never dreamed or even hoped to be a minister, but look where life has brought me," Mr Sampla told NDTV after being sworn in.
"When I look at the past 30 years of my life...I have worked in the fields. I have worked as a labourer. I was plumber in the Gulf, a technician, electrician..."
Even in his state of disbelief, he questions reporters, "If a tea-seller's son can become prime minister, why can't a plumber become a minister?" he added.
Mr Sampla admits he was shocked when he received a call about joining the government and doubted the caller. It was a call from PM Modi that finally convinced him that it was not a prank.
His inclusion in the government is apparently aimed at 2017 assembly polls in Punjab, where the BJP hopes for good returns from Dalit voters, who make up a third of the state's electorate.
His political journey began after he was elected the Sarpanch or head of his village. He has held several key posts in the BJP's Punjab unit.
Sources say the BJP's ideological mentor Rashtriya Swayamsevak Sangh or RSS played a role in his elevation as a union minister. The Sangh reportedly also threw its weight behind his national election campaign.