This is my completely subjective and unprovable theory about Yoonmin, but I have always had the impression that Yoongi has supported Jimin emotionally since the time the two of them were really young. He is one of the reasons Jimin stayed in BTS. He inspired Jimin to pursue singing because he knew Jimin had a unique talent. So I think because of that, because Yoongi was so emotionally available for Jimin it made Jimin want to support Yoongi in ways Yoongi needed help. Yoongi often struggled physically because of shoulder, or struggled to eat properly (it's mentioned in the BTS book), and sometimes struggled with mental health and Jimin wanted to give that energy back to Yoongi, that Yoongi gave to him. Jimin also always denied the idea that Yoongi was 'cold' or intimidating, which are stereotypes that still wrongfully get shoved on Yoongi even now. They're extremely sweet. I think Yoonmin have always been special to each other, I think they understand and respect each other very much and they're very special to me. I love that we know so much about them because of what they have said about each other in videos. I love my Yoonmin so much!!!