Comment by Pfhortune

You will continually get better at not just writing the right code, but at interpreting requirements into the right code. You will learn the edges and corners where bugs will hide. And sometimes you'll write them anyways, because that's life. You'll fix it in the future.

In this trade, a lot of orgs put a lot of emphasis on "sprints" and "deliverables", but you really have to look at software development as a continuum. Optimizations and bug fixes are a part of this continuum, and any good team has space for these things in planning.

Not all teams recognize this, however, and I would recommend discussing with the other engineers on your team how you can work together to advocate for this. No sprint can be 100% features. Software requires upkeep. Bugs are a natural part of this.