SHABDKOSH

मासूम बचपन कोई मुझको एक बार फिर से लौटा दें,, लापरवाही से भरी हंसी भूल गया हूँ मैं,
Ones again, someone my innocent childhood should return from me again.” I am forget laughter was filled with negligence

It’s wrong actually.
Someone please return my innocent childhood once again; i have forgotten (that/the) laughter with negligence.