In this talk, I plan to narrate the story of topological analysis of molecular electrostatic potential (MESP) from my group. My interest in this subject began in 1990 with the work in collaboration with Pathak [1]. This was followed up by detailed studies of topological features of MESP of molecules and anions [2], offering insights into the bonding and reactivity patterns. Important chemical features of substituent effects, aromaticity etc. were explored through the critical points of MESP. The first part of the talk will summarize these developments. The second part of the talk will discuss the calculation of MESP of very large molecules via the molecular tailoring approach [4] developed in my group. I will also briefly present our efforts for efficient parallel computation of MESP and its critical points [5]. The third part will deal with our recent work defining lone pairs [6] and their interactions with electron deficient π systems. Bader’s concept of atom-in-molecule (AIM), based on molecular electron density, was recently extended by us [7] by employing the scalar field of MESP. The portrayal of AIM through MESP showing electron rich atoms in the molecule as well as provides the details of direction of approach of an electrophile will be briefly shown.