What one virtue would you choose to have, if you had the choice to put that virtue on like a suit? This is almost like "what superpower would you want?," except virtues are real traits, held by human beings as psychological compasses that inform our decisions and actions. A few of the virtues I hold in high regard are:
1. Grit - Grit is like perseverance; to be specific, grit is persevering when the world is throwing obstacles at you, and doing this over long stretches of time. It takes Grit to complete an advanced University degree; it requires Grit to stay in a romantic relationship over years - without losing yourself and without forcing conformity from your partner; it takes Grit to create a company or a product when you have to spend thousands of hours at keying in all of the details and there is no guarantee that success is at the end of the road.
2. Honesty - Honesty is the light that obliterates the shadows of trickery and misdirection. Sometimes we need to hold out on information or tell little lies for the benefit of others, such as when we are planning a surprise or we temporarily want to get someone to do something that we truly believe will benefit them. But generally, honesty is the best policy. Lies have a way of growing and getting out of control, and can become so overwhelming from snowballing down the hill of fear (and fear is where most lies spring from) that it can be hard to stop a lie once it has become the monstrosity that is the destiny of serious lies. Honesty is important when building a trusting and healthy relationship with others, but it is crucial when communicating with yourself. If you are not clear and honest with your own being when it comes to your goals and your fears and when taking assessment of your current situation, failure at being the best version of yourself is almost guaranteed.
3. Flexibility - A rigid person may appear strong as they stand adamant to their beliefs and decisions, but when the winds of change blow hard, as they eventually will, the person lacking flexibility will snap and fall. Flexibility of thought is not the opposite of strength, but is an important complement to having a well-rounded and powerful persona. Flexibility doesn't mean swaying this way or that every time a little breeze comes through. Flexibility is being able hold a goal in mind while being willing and bale to change tactics when what we have been doing is obviously not going to work.
Back to the original question, what ONE virtue would you choose if you could suddenly become someone who embodies the principles of that virtue? I submit that a good answer would be to have the virtue of being highly CURIOUS. Be curious. Wonder Why? How? What? Who? "When is the best time to do this or that?" And "Where is the best place to seek out such and such?" By being curious, we are filled with the will to continue growing. If you think you know it all, then you are on your way to a boring death. The advantages of being curious, or full of wonder, are endless. From an empathetic standpoint, think about how powerful your interpersonal connections could become if instead of assuming that someone is just a jerk because they are acting in some way you don't approve of, you asked yourself "I wonder why this person is acting this way. What is going on in their life that is causing them to disrespect me? How can I bridge the illusion of distance between us by learning about the human-drama they are drowning in?" Curiosity is in contrast to complacency. Instead of assuming that things "just are" the way they are, you could imagine why they aren't the way that they could be, and be fascinated about finding a way to make things the way you would like them to be.