One good reason to keep sketchbooks, plural, is that the habit allows you to forget whole phases of ideas you were interested in for a while. They remind you of Ideas that ran aground at the time but which might be rescued when you catch them by surprise. There’s always a danger of an idea becoming a ploughed furrow if you work on it too long; very often it can become a trench and you lose sight of other ways to go with it.
I feel I have to clarify that the verb “keeping”. A lot of people just don’t. Keeping sketchbooks around has very little to do with sketchbooks, given the odd bits of office stationery, cheap notebooks, paper napkins, and margins of magazines that count as your sketchbook. And there’s the motley Art Cupboard of pencils, ballpoints, fibre-pens, crayons and whatever’s to hand that have to serve as your media.
Say, for instance, you have a flicker of a pretty simple idea and you don’t have a lot of light, and you’re working on an inside-out cereal packet with a chisel-ended Permanent Marker – it can happen – you learn very quickly the range of line you can coax from a green marker’s facets and figure out how to simplify the idea into the pen-strokes you can make on porous cereal-packet cardboard.
Or the skippy biro that refuses to draw a reliable line but works OK if you treat it like a pastel-crayon: each part of the drawing has to be brushed more than drawn.
That’s keeping a sketchbook: banging down reminders-to-self that’ll make reasonable sense when you find them later.
The great thing about stumbling on past experiments is that you’re less likely to get bogged down in the whatever-it-was that you were trying to capture at the time because you see it afresh: what you got instead of what you wanted. A lot of the possibilities you shaved off to reach the end you wanted can now suggest themselves afresh.
I have exactly this effect with crosswords. Late at night when you’re using the puzzles to club your brain unconscious you find yourself trying to find a way to jam a word you have in mind into a space that just won’t have it. Pick up the grid next day and often there’s one row with a few letters in place that immediately suggests a particular word that will fit and check the clue and find that it’s a coded description of the very word you saw at a glance.
Other people may point out to you that you always seem to be scribbling. Sometimes to be polite they’ll call it ‘sketching’ -‘you’re always sketching, you’- and you have to acknowledge that to many people this is a notably abnormal behaviour. Maybe anormal: not extravagantly extraordinary, but a bit …unusual. More unusual than the office character who’ll be the first to tell you that, ‘you ask anyone, they’ll tell you, I’m a bit mad, me’. (Actually, mention the character who elects to be the office crackpot to anyone else who works there and for some reason they have to take a quick look at the ceiling before agreeing that that is certainly one word for it.
It’s a pretty quiet, harmless eccentricity, so if making notes using pictures is handy for you, you can put it down to having a Primarily Visual Learning Style; then it sounds official.