What prepares one to take the step to be a priest or religious? Among other things, perhaps one of the greatest is charity or love. A vocation without love will become a cross rather than a joy. With a vocation for a lifetime, it must be love. Only love can last forever.
St. Therese was always one to discover certain fonts of grace in daily life that would help her to love. She tells the hilarious story of how she is washing with another sister who keeps splashing her with the dirty water. Rather than telling her to stop annoying her, she accepts them and as she says, "I decided to turn up as often as I could to that lucky spot where so much spiritual wealth was freely handed out." She also tells the story of sitting next to the most distressing nuns during prayer who annoy her with small noises. And she uses the opportunity to simply offer it as a prayer as she cannot pray with others.
In many ways, one prepares for the long haul, a life consecrated to God or the married life, by beginning with the smallest of things. Rather than complaining about that one thing that always gets on your nerves, start going out of your way to brighten the day of a co-worker who drives you nuts. I find this all the time in the seminary, whether it's fellow brothers who I much rather avoid than each lunch with or particular events in the seminary that become moments of interior complaining. But they can also be moments to love when you just don't want to or pray when you would just prefer to complain.
I think we are called, and I am so especially, to find those fonts of grace God has already put in our paths and that we constantly avoid. It is not easy but the practice of true charity will bring such good into the world and prepare our hearts to say yes to God in the smallest of things and the greatest - so that our yes today reverberates through our entire lives.