First impressions count and just as what you wear makes a difference, so does how you smell.

But have you ever really thought about how your perfume works? How it influences people around you?

Just like Ernest Beaux (creator of Chanel No 5) who said: “In perfumery the future lies primarily in the hands of the chemists.”

By being a bit science savvy you can use your smell to make your mark. I recently found myself swooning in the street having walked past a guy who smelled just like my first boyfriend.

Aside from embarrassing myself drooling over a complete stranger, I was blown away by how strong my memory of him was (and how positive!) just from a hint of aftershave.

It’s true! Smells are a seriously strong trigger for memory. This is partly because of the way our brain is organised – the smell sensor and your memory bank are neighbours in your brain.

It is also down to evolution. Before living things developed the ability to see, hear or touch they relied on smell to sense chemicals to source food and avoid poisons.

So if the way you smell is going to make people remember you then you had better get it right! What makes a perfume to remember? The first thing to consider is the perfume itself.

Science confirms that there is a difference between cheap and expensive perfumes. The recipe for an expensive perfume will include aromatic oils that can cost more than gold and have been prized for thousands of years. Aromatic oils are concentrated from natural sources such as frankincense, rose and sandalwood.

Cheaper perfumes have smaller amounts of aromatic oil, or none at all, and tend to have more “fillers”; things like alcohol and water. These fillers escape like steam from a kettle shortly after touching your skin.

Each perfume has a unique combination of delicately balanced layers of aromatic oils. There are typically three layers called head notes, heart notes and base notes.

The head notes are volatile oils that hit your nose first but disappear quite quickly. The heart notes are heavier, less spectacularly nose-smacking oils that are rich and hang around longer.

The base notes are the heaviest, most persistent oils holding the scent together.

But the perfume alone isn’t the whole story. I once had a glamorous French sales woman mysteriously whisper: “The perfume can only truly become yours when it is on your skin.”

Well she was right! Around 100 different smells can be detected on your skin, most as a result of the chemical reactions taking place in your body all the time.

This means that when you spray your perfume onto your skin you are effectively creating a new, unique scent that is a mix of smells from the bottle and your body. Whether you are on a first date, a reunion or a night out remember that your scent will linger in people’s minds long after it has left your skin.