The first job I ever had lasted three months.

I was 21 and management let me go, citing 'poor performance'.

It was my first sales job. Four months previously, I had zero interest in pursuing a sales career. In fact, I only took the job because I was desperate for the cash.

My dismissal at the time was both a surprise to both myself and the other team members, not least because my performance until that point had been quite 'middling' among a group of ten reps. However, I hadn't exactly shone, and there had been other members of the team who had consistently performed worse. Alas, they had bigger personalities and no doubt made me look like a shrinking violet in comparison.

Heads needed to roll, and mine was on the block in a sales team that wasn't delivering.

I meekly accepted management's decision without a whimper, promptly packed my belongings and left as quick as I could, still in shock. The one month paid leave offered little respite.

I was hurting. Bad.

I was so embarrassed. My career was barely three months old and I felt like such a failure.

This had been my first foray in the workplace. A shy, country boy from Northern Ireland and recent graduate - a degree in Accounting and Finance hardly earmarking me as the next Gordon Gekko - , working in the city of Dublin, hundreds of miles from home.

However, there are lessons in adversity.

In the weeks that followed, I reflected on what I could have done better. Deconstructing the best sellers I had worked alongside, I recalled their mannerisms, replaying their patter in my mind. How they had influenced customers to part with their money. Building rapport.

I began to consider what gaps were missing in my own skillset to excel. Could I have worked harder? Smarter?

As fortune would have it, there was a change in management in the organisation just two months later and they were recruiting again. Emboldened with fresh insights and with an axe to grind, I pestered my ex-colleagues to get me an interview, eager to demonstrate my worth.

When I spoke with the new manager, she must have seen how desperate I was to prove everybody wrong. She took a chance and so began a successful decade in sales, working for some of the largest tech companies in the world.

Had it not been for that dismissal back in 2003, my career path would have looked very different. Perhaps I would have closed the door on Sales altogether and discovered my love of software development sooner, but that is a story for another time. However, there is one thing that the experience ingrained in me - no one would ever dismiss me for a perceived lack of effort.

I worked harder than most from that point onwards.

It has been far from plain sailing, and there have been plenty of setbacks en route, but, recognising challenges and taking ownership of what is in your control - thoughts, words, actions - are all you ever really have in your possession. That's all you ever really need.

Outside of that, you are a feather in the wind.

You can't control the ultimate outcome. But you can influence it.

Only you know the score. Only you know if you gave it your all. Only you know if you tried your best. Only you know if you stopped short of your potential.

Manager fires you? Breathe. You did your best.

Economy crashing? Breathe. You do your best.

How you react to those events are what determines your fate.

Will you be paralysed by fear and turn away from the challenge or will you face the challenge head on, and tough it out?

Sometimes these setback can be blessings in disguise. We just don't see the opportunity in the moment.