Startup Strategy: A Fixed Passion and a Flexible Approach Know what you love and stick to it, but be willing to adapt your approach. Here's how.

In 1994, I left a job as a consultant at an insurance company with a big check that I viewed as an investment in my startup -- a firm that helps technology companies profit from growth opportunities -- based near Boston. I wanted to do work that I was good at and loved, rather than spend my remaining career navigating the maze of big-company politics. Beyond that, I did not have a clear idea of the specific steps I would need to get there.

What I did have was a fixed reason for starting the business -- an interest in advising high-tech companies on growth strategy -- and a willingness to be flexible about how I would pursue that mission.

If you love what you're doing, your venture will be more like fun than a way to make a living. Finding that focus is essential for startup success and if you do not feel good about your focus, stop what you are doing.

It's this balance between fixed values and a flexible approach -- one I believe every entrepreneurs needs to have -- that allowed me to grow my business to the point where I was able to invest money in other startups I believe in.

But the path there was not direct.

At first, I was helping publicly-traded technology companies in Japan identify, evaluate and profit from new business opportunities resulting from changing information technology -- most notably, the rapidly growing use of the Internet for business.

What I discovered was a valuable lesson for any entrepreneur: the market is a great judge of your ability. If you are succeeding, the market is telling you that you are better than your competition. If not, keep trying until you do.

In my case, an unexpected opportunity came along that opened up a new line of business. A client in Japan was asking questions about a study we had done on how U.S. technology companies survive waves of industry-transforming innovations.

That inquiry got me researching on the topic, which made me realize there was enough material for a book there. So I wrote my first book, which led me in a new direction altogether.

I believe it is a mistake to rest your entire business on a single product because demand for that product category can fade and leave your business fighting for cash flow. You must add new products -- but only those that tap into what you are good at and love doing.

I began giving speeches to corporate and business leaders at conferences around the world -- most notably throughout Asia and in Europe.

I was suddenly turning my attention to a new approach and ended up writing 11 books, which introduced me to business partners in countries such as Spain, Portugal, Singapore and China.

These countries were eager to replicate the entrepreneurial success of Silicon Valley and sought me out as an expert. I viewed Harvard Business School strategy guru, Michael Porter who helped countries identify their competitive advantages, as a role model for this kind of work. Through these connections, I was introduced to opportunities to speak at conferences and advise governments on startup-promotion policy.

Teaching seemed to me a natural extension of the consulting work I had done for companies. I learned a valuable lesson here: the need be open to learning new skills. When you broaden your venture's product lines, you will have to learn new skills. Before you start down that path, you should take a hard look at whether you think you have the will and the skill to master them.

While I had never envisioned reading and grading student's papers, I started teaching at Stanford, Columbia, MIT, the University of Hong Kong and Babson College. I did not think I would be a good teacher initially, but with experience and training, I got better.

In the last 19 years, I changed my venture's original idea -- from just consulting to consulting plus venture capital plus writing and teaching -- while maintaining its core focus on researching growth strategy for high-tech companies. I've been flexible about how I present the result and to whom.

What are some ways you have been both fixed and flexible in your own startup experience?