Lorelai, it was not you.
I, too, once flew next to a "leaner," a middle aged man who sat in the middle seat, but insisted on leaning at this weird diagonal angle that meant his head and shoulders practically rested on my head rest in the aisle seat. I don't know how he could wear his seatbelt and remain comfortable in his position. His head was RIGHT next to mine and if I wanted to avoid his noxious coffee breath, I would have had to lean my head into the aisle. And since I didn't want to be concussed by the drink cart, the following conversation took place just after take off, when it became clear he planned on staying in that position for a while.
Me: Sir, you're leaning too close to me. Could you please sit back into your own seat?
Him: My back is sore and I'm more comfortable like this. It's not a problem.
Me: Yes, but you're making me uncomfortable, which is a problem for me. So please stay in your own space.
Him: No, it's not a problem. I'm fine like this.
Me: But I'm not fine like this. You're in my space. Please lean back.
Him: I'm telling you, it's not a problem!
At this point, the FA came over to address the issue. She told the man that he couldn't lean that far into another passenger's seat. He insisted that he had to keep his sore back muscles in check. Since the flight wasn't full, she ended up moving him to a row of seats that was empty and he could lean to his heart's content. Part of me wondered whether that was his aim all along, to escape his undesirable middle seat. The other part of me wondered whether he was trying to look down my shirt.
Either way, I was glad he moved and couldn't believe how obtuse he was. HE didn't have a problem, so there was no problem!