An aphorism is a short statement of fact or opinion. They're often catchy and quotable. If you snooze you lose, All for one and one for all, Forgive your enemies but remember their names, Little strokes fell great oaks. Actually oaks feature quite a lot, From little acorns grow mighty oaks, Storms make oaks grow stronger roots, Today's oak is yesterday's nut which held its ground, The only cure for sea sickness is to sit with your back against an oak tree.
Even when aphorisms are opinion and/or wrong they're stated as facts eg Lightning never strikes the same place twice, Posession is nine tenths of the law, All things come to he who waits.
Sometimes they're designed to encourage better behaviour or spur us to action, If you're not part of the solution you're part of the problem, Genius is 1% inspiration and 99% perspiration, Nothing ventured nothing gained. They can also suggest a deeper meaning, All that glitters is not gold, You can lead a horse to water but can't make it drink.
Aphorisms often contradict each other, Oil and water don't mix, Opposites attract, You're never to old to learn, You can't teach an old dog new tricks.
One of my favourites is, Keep your powder dry. It's good advice.