Launching a startup will toss your emotions around like a roller coaster, with mountain top highs and devastating losses. But pretending that your co-founders and other entrepreneurs aren’t dealing with the same emotions will perpetuate an unhealthy myth — — further isolating you, draining your confidence in your own abilities.

After years spent growing business after business, as a co-founder at Performable, which we sold to HubSpot, and FreeLogoServices.com, my current startup, here are four emotions that I’ve faced on a daily basis.

Fear.

Every single entrepreneur faces this emotion — and most of the time represses it. I’ve watched businesses lose three-quarters of their team to layoffs, and I can attest that fear is one of the lowest feelings you can have. According to a University of Colorado study on, Emotions & Entrepreneurial Opportunity inducing fear in participants caused them to perceive a choice as being riskier than other emotions, like anger. However, winning the game requires sending the right people onto the field at the right time — and sometimes that means making cuts. Whatever gut-wrenching situation comes your way, leverage it as a godsend. Trust your intuition. You have to, for the long-term health of your company. Fight for your culture and mission above all else, and trust me: the toughest decisions are best made sooner, not later.

I have faced situations that would make any entrepreneur’s heart race: firing people, laying off 20 percent of my team at once, and 90-day deadlines that carried the threat of a shutdown. All were things I feared. Fear is good — it means you are moving forward. If I had avoided the fear of making challenging decisions, the companies I’ve founded would have died.

Curiosity.

Startup success pivots on ferocious curiosity. Only by continually peeling the onion on customer and business needs can a great idea grow into something real. But growth also requires change, which requires flexibility. At FreeLogoServices.com, we hold “Experiment Meetings” each week, complete with white lab coats embroidered with our company logo. I know that if my employees don’t feel empowered and confident to try new ideas — and even fail in the process — we will never move forward.

Picture a company with no curiosity. (Maybe you’ve worked in one!) It’s probably a place where the same people have operated the same way for many years, despite major advances in technology. They may adjust to meet an imminent threat, but never go out of their way to innovate. An existing company with this kind of attitude may be able to scrape by, but won’t grow long-term; a fledgling startup would never even make it out of the gate.

Doubt & Anxiety.

Learn to distinguish between insecurity and anxiety. Insecurity is an excuse — your inner critic telling you that you don’t have what it takes. Anxiety is a normal and healthy reaction to stress; it’s your body telling you that you’re about to make a big decision.

As an entrepreneur, sometimes you will have all the data to make a decision — and sometimes you won’t. No matter how much you’ve pored over the numbers, there will be times when you’re unsure about the next step. Don’t over think decisions you know to be right. After you’ve researched your options as thoroughly as possible, trust your own instinct.

Excitement, Passion & General Euphoria.

Some days, the life of an entrepreneur is just hell. You are guaranteed to have those days, the same as every other entrepreneur. You should also feel a satisfaction that is larger than life as a passion for what you’re building continues to evolve. According to the University of Colorado study mentioned earlier, happiness actually makes entrepreneurs predisposed to see less risk — in other words, more confident about risk taking.

If the euphoria, of building a business, doesn’t buoy you on a daily basis then do something else with your life! That innate excitement signals you’re doing what you should be doing, and it will warm you when the fear and loneliness of being an entrepreneur threaten you, and your business.

Do you know the best thing about startups?… You only ever experience two emotions: euphoria and terror. And I find that lack of sleep enhances them both. — Marc Andreessen as quoted in Ben Horowitz’s book “The Hard Thing About Hard Things”

What’s the point?

I’m the first to credit success to carefully gathered data. My company uses data in making every major decision, but logic and emotion aren’t mutually exclusive for an entrepreneur — it’s crucial to employ both areas of the brain with each decision. In fact, ‘gut feelings’ are our brain’s way of sorting through the facts. Neuroscientist Janet Crawford put it this way:

…emotions are elegant shortcuts that allow us to sort through reams of [subconscious] neural patterns and generate feelings that guide us toward or away from a course of action. Without emotion, we are biologically incapable of making decisions. Logic is often the last step in the process.

In other words, when we dismiss our emotions to make a big business decision, we’re rejecting our body’s own way of analyzing data. So, acknowledge emotions as you make business decisions.