'Vitarka badhane pratipaksha bhavanam'
When disturbed by negative thoughts, opposite [positive] ones
should be thought of. This is pratipaksha bhavana.
The Yoga Sutras of Patanjali - 2.33
This quote comes from the second chapter of the Sutras - an important work on yoga philosophy and practice.
'Sutra' means thread and Patanjali's short statements certainly come across as fragmental when you read them. But the idea is to enrich these threads with interpretation, weaving them 'into a garland of pearls of wisdom' (Light on the Yoga Sutras by BKS Iyengar).
Several translations and interpretations have already been published by famous yoga teachers and they can differ a fair bit because there are disagreements on the exact translation of the original sanskrit wording. (By following the top link, you can see which version I am reading from.)
So, what Patanjali might be saying here is simply to cultivate love towards the things you dislike. Alright, so maybe it's not so simple to be loving towards that work colleague that always pushes your buttons, but that is the idea here.
On your yoga mat, you can cultivate love towards the asanas you are not very good at/can't do as they are probably the ones you dislike, and most likely the poses you need to work on. It is when we come up against these challenging poses that we tend to either apply (too much) force or give up (by making an excuse we can live with).
The next time you step onto your sticky mat, take a moment to analyse your pre-existing negative attitude towards a difficult asana, then try to better yourself as well as the pose.
