The Parasha / Torah reading of Ki Tisa Hash-m / G-d tells Moshe “When You count the heads of the children of Israel – you will take an atonement for their souls. And their shall not be a plague among you.” (Shemot / Exodus 30:12)
The Torah does not use the Hebrew word for “Count” it uses the Hebrew word “Tisa” which means uplift. Meaning when we encounter a person – it is up to us to uplift them. Help them reach a higher level spiritually. Say a nice word. Smile. Teach them some Torah thought.
In Pirkei Avot (1:12) it says “Be like the Disciples of Aharon HaCohen (Aaron – Brother of Moses) – Love Peace and Pursue Peace – love the creations and draw them close to the Torah.” That’s how we lift others up – by drawing them close to Torah.
Making others feel better makes you happy as well. It works both ways – we should be happy – and that will overflow to others. But also when we rejoice others it makes us happy. Why? Because doing a mitzvah (of making others happy) gives joy to the soul.
The Jews would count by means of each person giving half a Shekel coin. They would then count the coins. Thus the eye would not be focused on the people but on the coins. Something that is counted limits it and limits the blessing. When the blessing is limited the “Evil Eye” can affect it. Thus by counting coins instead of people – it prevents a plague from happening to the people.