The only guarantee with entrepreneurship is that you will have challenging times. Perseverance has more value than growth, especially since your business's success depends on the economy, the timing and several other factors out of your control. Ironically, the best way to make a better future is to truly embrace where you are now-- and write it down.

High performers from Tim Ferriss to Mark Cuban swear by taking the time to reflect (in longhand) on your day. It could be first thing-- the so-called morning pages-- or the evening setup reflecting on your day. I do the latter every evening after a short meditation. It has been invaluable.

This is why journaling is even more powerful during times of stress.

Your memory is unreliable,

Pull out Nassim Nicholas Taleb's classic The Black Swan. It is worth reading in its own right as it's about how unexpected events effect history way more often than our best guesses, but it also has a great passage on why you should journal:

While we have a highly unstable memory, a diary provides indelible facts recorded more or less immediately; it thus allows the fixation of an unrevised perception and enables us to later study events in their own context.

We can gather insights after something happened, but we don't remember how we were processing things while they happened.

In the book, he points to several major events-- World War II, the modern conflicts in his homeland of Lebanon, and so on-- where people believed the new event would be over quickly. Some diary writers said they thought the World War II conflict would be done "in a matter of weeks." Chances are that they remember believing something different. We automatically reframe the truth in retrospect.

It is the only possible way to learn from the past.

How did you navigate your biggest challenge, say, five years ago? As I write this, we're talking 2015. Chances are you don't remember the feelings you navigated, the insecurities you overcame or the ways you grew. If you do remember, your view has been shaped by almost 2000 days of experience.

Your view is tainted, abstracted and revised. It may be worthless now, unless you wrote things down unfiltered. I'm fortunate: Not only was I keeping a journal on-and-off, but I was writing this very column. I (and everyone else who follows my column) know exactly what my biggest challenge was in 2015. But the words are foreign to me, because I remember my startup acquisition experience differently.

What happens when you have another tough time? Will you forget what was learned, what you felt and how you overcame?