Why does my life feel meaningless if I'm not changing the world?

People like yourself who grew up in the public school system were told you had to change the world, that you had to do something enormous with your life. The reality is that's not real for most people. Most people end up in a pretty mundane type of life, and not everyone is curing a rare disease. When you set yourself up for that super high expectation, you end up frozen, because what you're doing seems insignificant since it isn't grandiose.

But this is not what God designed us for. Most men lack meaning today not because there is nothing meaningful in their life, but because they have not embraced the true purpose of life. Man was created for God, created for communion with God, where God is constantly pouring into him and he is pouring himself into God. When that dynamic is replaced with a self-referential life built on accomplishments and how you appear to other people, life becomes hollow, because you're not in connection with the one person who gives you meaning. St Paul writes, work as unto the Lord. Even your job should be as though God himself is your employer.