Kelvin knew it from the beginning and he followed his principles; which will not be a conscious effort from him but rather a habit, a character attribute. He is known in the neighbourhood as the 'infinite cool' guy with his gentle and charming nature. The girls of the locality loved the cool guy but our 'infinite cool' guy was also an 'absolute zero'. He never really intercepted or responded to any of the signals.
If Kelvin is our meekly guy, who we may think as a hero in this little story, then we also have a villain. His name is Pascal and he has a ugly gang called Cabinet. Everyone knew him as Big P. He is fat and does not have any manners; scratching and spitting in public being his favourite pastimes. When he anchors his heavy legs and starts cursing a local kid while his Cabinet isolates the kid in the middle of a public place, then that kid will become a wimpy person for life. Unfortunate. Gabbar would be put to shame by Big P. There is one and only way to escape the wrath of Big P. Say the L word and you are free to go to your mother unharmed. The F word is known to everybody, Big P had made his own dictionary and the L word was his favourite.
Kelvin is little different as he is the cool guy. He has a control on his temper and could withstand hostility. So, he is the natural enemy of Big P. No torture could force our meekly cool guy to say the L word. Big P even tried his deadly crocodile death roll but mental or physical, no pressure from Big P aka Pascal could deter our 'absolute zero' with his 'infinite coolness' to buckle and say the L word.
Sometimes situations become really frustrating and during these angry moods, Kelvin feels the need for the L word and remembers Big P's ugly dictionary. Kelvin will remember his father's words "Life’s disappointments are harder to take when you don’t know any swear words". Gradually Kelvin will learn some basic vocabulary and top that up with a bang on a table in angry moods.
It so happened one day, Big P was being sent across to the West coast for good. He was notorious but good. He made the kids stronger to take on the cruel world. He used to force the kids to get out from the safety of their cocoons. He also gave them good food sometimes. Kelvin knew all this. So, he broke away his shackles, in a way, as a farewell token. He wrote the L word and signed Kelvin.