Matthew Parris did a good list of advice to his 16 year old self a few years ago. It’s basically just a mixture of different kinds of advice, but there’s some fairly insightful stuff there:
Socks: buy ten pairs of black cotton socks and ten woollen; and stick to black for the rest of your life, saving hundreds of hours trying to match odd socks.
Never kid yourself you can make something of somebody; instead, find someone who’s making something of themselves, and help them, otherwise years can be expended trying to push the human equivalent of a wet end of spaghetti up a wall.
Never accuse someone of stealing unless you’re absolutely sure.
Never underestimate the pleasure that can be given by cancelling a party: busy friends love an unexpected diary window.
Be brutal about wedding invitations: there are only so many Saturdays in your life.
It seems to be a marked contrast to the rather tiresome messages along the lines of “Don’t Ever Give Up” and “Suffer Continuously For Your Passion” and “If You Don’t Have What You Want You’re Not Trying Hard Enough” and such forth. How reasonable.
Most of it’s pretty good, with one glaring exception.
#2 - Trust your instincts
No. Shut up.
I know you mean well. But trust your instincts is a bull$#@! rule. Listen to your instincts, absolutely. They provide valuable information, and you disregard it at your peril.
But your instincts are not magic, and sometimes the key to life is OVERCOMING your instincts. Do not trust them blindly.
On a personal level, trusting my instincts means throwing away most of the other advice on the list. Trusting my instincts means never talking to another human being unless absolutely necessary, because every instinct screams against it (and for that matter, it probably means nobody wanting to talk to me either because I’m awkward and will trigger their ‘this guy’s not right’ instincts).
Listen to your instincts. They’re a helpful tool that may point towards important stuff you missed, or provide a better-than-average direction you should take when you’re on the fence about a decision. But like any tool, you still have to use it wisely, don’t just rely on it to always work.
I think it’s worth remarking that, IMHO, the above comment is essentially an extemporisation of the core path to wisdom.
(just because I recognise the signposts doesn’t mean I think I’m there yet