New Experiences Yield New Worlds

When you have a new experience, it opens a new world to you. Until you work an office job, you  can't really understand what is going on in an office. For you to write about it, you would be guessing and basing it on stereotypes and things you've heard about it. The same is true for going to a live concert or tailgating at a football game or getting a prostate exam. Afterwards, you understand it intimately and can talk about it with certainty.

It's pretty common advice to tell writers to "write what you know". The problem is that if you don't know very much, you become so limited in scope. The more experiences you have, the more subjects you can talk about with knowledge, the more worlds you will be able to make use of in your writing.

These worlds can be major or minor aspects of your writing. You don't need to write about the life and times of office drones, but if you understand what that white collar job is like, you will know the kinds of vocabulary they use, the things they talk about, and the motivations for the things they do outside of work.