Shailendra died on 14th December 1966, which ironically was the birthday of his closest friend and aid Raj Kapoor, who was emotionally broken by his death and said "of all days in the year he chose this day to leave the world".
In those days, famous composers would recommend lyricists to producers. Shankar-Jaikishan had promised Shailendra that they would recommend him around, but didn't keep their promise. Shailendra sent them a note with the lines, "Chhoti Si Ye Duniya Pehchaane Raaste Hain, Kahin To Miloge, To Poochhenge Haal". Shankar-Jaikishan realized what the message meant and having said sorry, turned the lines into a timeless classic song for the film "Rungoli".