TL;DR
There is saying that if your task makes you dull, you are doing that task wrong. It is basic psychology why some jobs are more fun than others. We will try to provide advice on how to make tedious tasks more fun. The post is based on a remarkable book written by Chad Fowler, The Passionate Programmer.
Tasks that do not use your creative mussels are tedious tasks. Programming is a creative task, so many software testers that I have met strive to become automation experts. One of the main reasons is that they have never seen experienced software tester doing his work. To make tedious tasks less boring, we have to make them more creative.
When you need to write documentation, use that time as an opportunity to practice typing without looking at the keyboard. That trick helped me to make writing documentation more interesting.
To avoid boring, repetitive regression testing tasks, I learned to read the programming code used in the project along with frameworks and libraries used in the project and written in that programming language. Now I need to do a full regression test once in a year when core framework is updated. On all other occasions, I do not do a full regression test because I exactly know which part of codebase changed and how that maps on the application features.
If you think that software testing is just checking by specification, head your browser to the BBST side and make your testing more fun.
You wrote automation code, but you hate writing unit tests for that code? Set a goal that you will achieve 95% of statement and branch code coverage and make unit testing more fun! Learn vi editor keyboard shortcuts and used them in your favorite IDE because all modern IDE have vi keyboard shortcuts plugins. Editing will never be boring again.