On not talking One of the most satisfying practices is the practice of not talking. Luckily for you, you don't seem to have a problem talking for a long period of time about nothing. This means you have confidence and conversational skills, which are both great things to have. However, having these things means that your reservation and ability to stay quiet are all the more valuable. Every time you decide to stop talking and spend your time only listening to others, it's an entirely different experience. Good—you should be doing that more, because in the end, your words are entirely lacking in significance, and you might as well hear what everyone else has to say before you try to make any points of your own.
On bad conversation When I say bad conversation, I simply mean conversation that is going nowhere or is intensely boring. This happens a lot. It seems as though when you leave the conversation the activity level of the group as a whole drops. That's okay, but also speaks to a disparity—your talking was filling up the group with conversation, but mostly with your own words. Learn to spur other people on in the conversation with as few of your own words as possible. Yield to them. When the conversation is boring, so what? It's not your job to change it to be better or more right. Your first job is simply to listen.
On insignificance As you learn more and come across more people and more situations, the horizons of what you don't know expand just as much as your knowledge and experience. This can be an uncomfortable feeling, and I've noticed that you do seem to be a little uncomfortable in these moments. Largely, this is because everything seems to challenge your significance as a person. If you stay in a smaller and smaller bubble of a world, of course it's easy to feel like your thoughts matter in some capacity. This isn't to say that your thoughts don't matter at all—they do—but simply that your thoughts and views on the world are not nearly as important as you (or others) might make them out to be. You, like every other writer, will leave behind only the words you have written on paper and spoken on a recording. That is it!
On significance At that point, your most tangible positive effect on the world will be the actual people who you helped and guided to make them better. That is what you should focus on. Love more. Love relentlessly, for the people you love will experience and feel that for a long time to come. Love in whatever way you know how—perhaps this comes through your writing. Maybe all of your writing is due to the fact that you want to be able to give your words and thoughts to others and help them along their own path. That's why you do it, so keep doing it.