Ash makes many good points, but especially that chemistry underlies all the biology and physics and engineering that we see about us. Without chemistry (the design, synthesis and understanding of materials) we would have none of that: nothing from the early smelting of iron and bronze, through the Romans' skills with glass, right through to modern concrete and carbon fibre.
Yes, chemistry encompasses everything from the synthesis of smelly bubbling green liquids, through the power of detergents, to a deep understanding of molecular structure via spectroscopy (which is what I did) and quantum mechanics.
All of this is chemistry. And it all underpins our world, both artificial and natural. Without chemistry we wouldn't have modern anti-cancer drugs, or modern anaesthetics; we wouldn't understand the biochemistry underlying photosynthesis; we wouldn't have air-bags in cars or rockets that can take us to the Moon and beyond.
That is why I trained as a chemist. I wanted to understand how these things worked. (Although I probably couldn't have put it is so many words at the time.)
And I am still sad that I had to give it all up because the mid-1970s recession meant there were no sensible jobs for chemists. That's what happens in a recession, we lose the skills we've invested in, because no-one can afford to invest for the future. I can understand why, and it is a fine line to walk, but it is short-sighted especially when the education system is so unattractive as a job option that those who are displaced are lost to the discipline and not even attracted to teach and enthuse a future generation.
Would I do things differently if I had my time over again? Probably yes, if I knew then what I know now. I would certainly have worked harder (not difficult) to stay in research. And I might have looked more favourably on teaching. I certainly would have liked to continue as a working scientist rather than "selling out" (as my father saw it) to commerce. Science is much more fun that selling things.
Could I go back to it? No, not now, after nearly 40 years out of the field — much as I might like to. But at least I have retained a broad interest in science, and not just chemistry, so with luck I can still enthuse a few others along their path.
And it is still the simple things in science that enthral me. How metals are smelted. Why snowflakes have six-fold symmetry. How compounds are light sensitive. How detergents work.