Om Swami
How can I stay humble when good times come into my life?
Bow your head when happiness comes
For a sattvic (pure, balanced) person, happiness arrives with a bowed head, while an egoistic person's head rises first. Tagore's prayer is to recognise the Divine's face in joy when it comes.
For a sattvic person, happiness always comes with its head bowed. For an egoistic person, when happiness comes, his head is the first thing to rise.