In the beginning, I thought I need to have emotions to manifest something, but lately I experience more and more that little thoughts without much emotions in it manifest. For example, I completely randomly thought about someone stepping on my foot and a few hours later, I stepped on someones foot. I haven't so much emotions around that topic normally..lol.
I haven't figured that out completely yet, but I think every thought has an effect on some level. But you can undo those thoughts by thinking a contradictory thought. It's the same "technique" that is the reason for people not getting back with their ex or needing a long time to get back together - they cancel out their own energy. But in this scenario, you use it consciously for your advantage.