We are all world experts at rationalization when we want something enough that fulfills a need or if the temptation is great enough
The funny thing about rationalization is that it blocks out reason, perspective,ramification, clarity but this is good news
Because if we can talk ourselves into anything that gratifies the body and our baser desires ,temptations etc we can talk ourselves out of them and we talk ourselves into 
non fleeting gratification of the soul
healthier habits
positive behavior
being self confident
leaving our comfort zone,achieving the impossible
being more motivated,inspired etc
feeling happier
gaining better perspective
never giving up etc etc
The sky is not the limit but rather the ground we walk on when we channel the super power of rationalization in a positive, more pure, soul based direction,we can talk our selves into anything
BUT
We have to WANT it badly enough,it has to be a priority , a FOCUS,we have to believe it and let it into our hearts
AND
We have to learn to rearm our self talk arsenal to suit what we wish to change , improve ,upgrade etc and if you are finding difficulty, get outside help it is worth the effort.With a suitable self talk arsenal there will be no limit to what you can talk yourself into achieving