Most days, I don’t feel particularly special -- well not due to my gender, at least. Most days, I try to hit "in-box zero" state but fall further behind on my to-do list and do my best to grow my company. Most days, I enjoy my co-workers and fire off a few rubber bands from the rubber-band guns we have around the office.

Some days, however, I feel different -- like last week at a human resources and marketing conference, when I realized that there was only one female speaker out of 15. Then there was the time a few weeks ago when my company's CEO asked all the men around him about their favorite sports and left me out of the conversation. And it hits me every time the web explodes with yet another gender-related story or hashtag.

I am a woman. I am not a programmer. I even turned 40 this year. And a year ago I was the first person a CEO hired when he relocated his startup from Sydney to San Francisco. 

Related: 10 Apologies I Will Never Again Make as a Startup CEO

My company originally started in Australia in 2011 and has four male co-founders. They bootstrapped the company's launch and raised a small round of seed capital and the firm expanded to the United States a year ago, placing its headquarters in San Francisco. The founders hired me away from Amazon to be their first U.S. employee as "head of growth." Yes, they call me “HoG” to my face and then have to duck my rubber bands, although I'd like to point out that I'm much better at ducking than they are.

I was one of two women who applied to RecruitLoop’s head of growth role out of more than 100 applicants. I applied because I felt like the job description clicked with me somehow. I’m still not sure whether my skills fit the requirements. I wasn’t even sure I wanted the job. I was looking at operations roles, not growth roles. When the CEO emailed me to ask for a meeting, I took the call.

After some conversations via Skype, a project and a breakfast meeting in Mountain View, Calif., we agreed that we wanted to work together. And a week after that, we stretched our financials to the limit to arrive at an offer that the co-founders and I could live with.

It sounds easy, doesn’t it? Then why don’t more women join tech startups early on?

You want to know why? Women aren’t applying to these jobs. Whether it’s because women think they need to have 100 percent of the qualifications of a job to pursue it or they want more generous maternity leave, women are taking themselves out of the running.

And it's awfully hard for someone to join a startup if she doesn't even apply.

Related: Team 'Ban Bossy' or Not: 3 Reasons Why Hiring Women In Tech Grows Business.

You know why else? Women have to deal with the double take. They have to deal with walking into a room and feeling out of place, or recover from the many times of being excluded from a conversation by body language or dropped from the distribution list on an email thread. Women have to suck it up when the CEO asks everyone else (who's male) about a favorite sports.

It becomes a bit tiring. Even at companies like mine where the co-founders want to hire and advance women, these things happen. Like any new exec at a startup, I’m not automatically included in things. And when I become worked up about the latest hashtag, I wonder if it’s because of my gender. I go home to a husband who only understands somewhat (since he’s a startup guy himself), and I don’t have many other female friends at startups who can commiserate. Some days, yeah, it’s hard.

But things are becoming easier. I’m kicking down doors when I realize they’re closed. I called out my CEO when he didn’t ask me about sports (I’m a huge sports fan). And I finally asked about the late-night co-founder call that excluded me. (It turns out that I didn’t want to be included.)

Luckily, most days aren’t days when I feel like my gender matters. I firmly believe that if more women applied to jobs that weren’t exactly right for them and more founders kept an open mind about age and gender, I’d have a lot more peers in this thriving startup scene. At this point, though, I’d love to hire another woman in the San Francisco office, but that’s a story for another day. 

Related: Do Women Leaders Walk a Tightrope to Be Seen as Effective and Likable?