An interesting study published 2019 in the journal of health psychology, reviewed lots of studies conducted on what is called mental contrasting.
Mental contrasting is a behavior change technique the essentially involves three steps:
Definining an important wish, or positive future scenario.
Fantasizing and actively visualizing the best possible outcome of that scenario.
Identifying and visualizing current obstacles that stand in ones way of realizing the future scenario.
Previous research has shown, in contrast to what one might believe, that only fantasizing about a positive future, actually has no bearing on ones intention to realize that future, and in some cases seem even to be detrimental for behavior change. The reason seems to be that this process alone acts as a form of low-grade substitute of the actual thing, draining cognitive resources and lowering blood pressure, which is an important marker of behavioral intent.
Therefore, mental contrasting has been designed as an alternative to wishful thinking, that can actually lead to some form of action towards goals.
In reviewing hundreds of studies, 27 studies were picked out and analyzed to review the evidence on this method. In this review, researchers found that mental contrasting seemed to have significant small to moderate effect sizes on changing health behavior.
What made this finding even more interesting, is perhaps the simplicity and low resource demand of the method, wherein one self-administered session of just one hour of mental contrasting, seemed to be enough for significant and long-standing effects.
So when attempting behavior change, it is important not to get lost in ones fantasy, but also concretely contrasting that fantasy to reality. And then to start acting.
Cross, A. Sheffield, D. (2019). Mental contrasting for health behaviour change: a systematic review and meta-analysis of effects and moderator variables. Health Psychology Review. 13(2). 209-225.