Expertise becomes larger when shared with people capable of carrying it further.

Knowledge kept to yourself is capped by your own time, energy, and lifespan. Given to people who can take it further, it grows in ways you could not have produced alone, and it comes back changed and improved. Hoarding it preserves your position and limits the thing itself.

Find someone with the capacity to go past you and give them what you know without holding the best parts back. Their progress will not diminish yours. It is how anything gets bigger than one person.