"If I knew then what I know now" is a weekly series of essays by small agency owners about lessons they learned in building their shops.

If I knew then what I know now, I'd tell myself, "Breaking through takes time – it's a function of willpower and perseverance."

At Portal A, we're lucky to work with some of the biggest brands and most exciting talent in the world to create videos that are seen by millions of viewers. We have a team of 50 amazing employees based in our offices in San Francisco and Los Angeles. And we've become one of the leading branded and original content companies in the digital space.

It's taken years, but people are finally starting to sit up in their chairs and take notice.

This was not always the case. The early days of the company were lean, to put it mildly. We've always been bootstrapped and independent, without a cent of outside financing, or a rainmaker to make calls for us, or a client to build the business around. We had no film or advertising pedigree and no industry relationships. Which meant that square one really felt like square zero.

We worked out of a moldy basement. There were a lot more emails going out than coming in. We jumped at every opportunity, no matter how small. But we knew that the models for entertainment and advertising were shifting, and that we could play a central role in that change.

While my partners and I enjoyed the hustle in the early days, we each had an assumption that there would be a single blinding moment of truth where we would transform from Urkel to Stefan.

That moment, of course, never happened (or if it did, we missed it). The truth of our journey was that we built the company – brick by brick, project by project, client by client, relationship by relationship – over the course of nearly a decade. And it wasn't easy.

If I could talk to my younger self, I would tell young Zach that bootstrapping a company in a new space can be the most meaningful challenge of your life, but to be prepared for the sleepless nights, the weekends in the office, the doubt and anxiety, and the crises both unforseen and self-inflicted that it would take to get where you want to be. And we still feel like we're just getting started.

The struggle is what made the journey rewarding. And the journey never stops.

Zach Blume is co-founder and managing partner of Portal A