It was six o’clock in the morning and I was trying on sunglasses in duty-free at London Heathrow. The shop attendant approached and started to chat.

"Early start this morning. Where are you headed?" he asked.

"Paris," I replied. Or I think I replied. It could have been Brussels, or Amsterdam, or Milan, or Copenhagen. Early flights were my specialty last year.

"Ah, nice," he continued, tidying shelves as he chatted, "this time of day it must be a business trip. No-one gets up this early voluntarily. Where do you work?"

"Microsoft," I said, putting a pair of RayBans carefully back on the display.

He stopped tidying. "Wow, Microsoft," he said, "Have you met Bill Gates?"

I have had variations of this conversation countless times over the past 17 years. Each time, even when followed by technical complaints about Outlook, I have felt immense pride. Pride to be working in a job I love. Pride that millions of people use the products we created. Pride in being associated with Bill Gates. Pride in working for a brand name that everyone recognises.

In recent days, this conversation has changed. I was standing outside the school gates last week, waiting for my daughter, and another school mum turned to me.

"Where do you work?" she asked "You are sometimes dressed in running clothes, sometimes in suits."

"Microsoft," I replied "I’ve been there 17 years but I am leaving next month."

"Wow, Microsoft," she said, "Why would you leave?"

For years, when I considered leaving Microsoft it made my stomach hurt. Microsoft feels like home. It is comfortable, it is familiar. Having worked there for more than one-third of my life, Microsoft is part of me.

But this year, moving on is the right thing to do. I thought when I left I would need to go to another recognized brand, another company whose name would elicit that same Wow response from strangers. Instead I have realized the person I need to wow is myself.

So. I am moving on, not to another multinational but instead to start my own company, Be Leadership Ltd. I couldn’t be more excited.

Wow, Microsoft. Thanks for the learning, the challenges and the preparation for what’s next.