Act the way you want to become until you become the way you act

Actress Kelly Reilly plays Beth Dutton in the smash TV series Yellowstone. One of the most talked about characters of the series, in a recent podcast Kelly talked about playing Beth, "I lean into Beth with how she enters and owns a room. I don't necessarily share that quality, in fact I don't share it at all. But when I play her for a while I start to understand the strength in me that can do that, and I've limited myself to thinking I can't do that.... just by my brain. But when I play her I can do it...so it's already in me, we are all capable." 
This is such a great insight from Kelly and it's also a good example of what Todd Herman wrote about in The Alter Ego Effect. Effectively Kelly is using Beth as an alter ego, that by acting like Beth she overcomes her own self imposed limitations.  Create your own superhero, step into their mindset, their characteristics, attitude and if it's positive, it can take you beyond what you, in your character thinks you can't do.  Act the way you want to become until you become the way you act.