It's also true that saying "just" does not make a difficult thing into "a snap" that takes no time or effort at all.
I've been counseled to "just get up and ski," as if "just" alone would keep me upright and instantly able to advance beyond snowplow technique, never mind the icy conditions and stinging sleet.
I've been told that all I have to do is "just sit down and write it," when what the guy wanted was for me to turn a talk I'd given into a paper for his journal for free.
I've been advised to just get a fellowship to finish a book. Well, I've managed to get a number of fellowships, and each one has taken quite a few days of work and then months or years of waiting. Sometimes it has taken being rejected a number of times before getting the award. Some plums I've gone after continue to resist me. I've been told in advance that I don't have the proper academic credentials and that my project doesn't match their parameters. Once, after massive effort and long wait, I was put on an a waiting list, but no one dropped out, and so I reapplied and won on my second try the following year. I did finally get there, but it wasn't a matter of "just" filling out a few forms.
Probably you too have been told to just relax, just tell so-and-so what's-what, just stop thinking so much, just get a master's degree, have another baby, and get a grip.
"Just" can cut through the procrastination and rationalizing. After that, it helps to apply strategy, effort, patience, hope, and the courage it sometimes takes to keep going. It helps to know in advance that it's not always "just" a "piece of cake" and easy as pie. It's also important to give ourselves proper credit for our work along the way.