Here's what teenage me didn't know was coming

I'm 100 per cent certain another sharemarket sell-off is looming. How do I know? Because there's never been a point in my life where there wasn't a crisis, panic, recession, crash, bubble, sell-off or bear market around the corner.

If I talked to the 18-year-old version of myself, I could whisper a few secrets in her ear to prepare her for the future. Yet the investment advice that follows is barely believable, given what's about to happen in her life.

Perhaps I'd start with the big picture.

Listen up my dear, because in the next 30 years, the global markets are going to make you suffer through 17 major meltdowns. You'll be getting a couple of five-year gaps for a breather and outside that, they'll be smacking you in the cheeks year in, year out.

How do I get her to start saving when I've just revealed those stats?

Well let's start right back at the beginning.

New Zealand will suffer more than any other economy in the 1987 crash. It will alter the thinking of a generation. Your first lesson is never own a New Zealand-only investment portfolio. We have an extremely high concentration of risk and a tiny economy. I can feel the 18-year old me squinting in disbelief already.

Let's tell her about war. Iraq will invade Kuwait, US markets will plummet and a recession will take hold. You'll see atrocities in Bosnia, Kosovo and Syria. A decade after Kuwait, aeroplanes will purposely fly into two of the world's tallest buildings and a war on terror will begin in Afghanistan. My advice? Just keep investing through the bombs. Don't forget commodities as an asset class; oil prices like unrest.

She's fascinated by currencies. Soon there will be no marks, francs, lira, schillings, or drachma. You'll see 20 of the worlds currencies fold into th euro. The British pound will crash out of the Exchange Rate Mechanism and a man called George will make a $1 billion betting against it. The UK will be thrown into recession.

A few years later the Russians will devalue the ruble and default on their debt. Don't fret my dear, keep investing those dollars.

Snap crackle and pop doesn't just apply to Ricies. Bubbles are everywhere. The longest lasting will be the Japanese asset bubble. It'll span 20 years. Property prices and sharemarkets will dive and deflation will take hold. You'll even see negative interest rates. Keep investing, but don't put big bets on single countries.

In a few years the internet will go public. You'll send letters via a computer and use it as an encyclopaedia. By the time you are 30, share prices in tech companies will form a giant bubble and pop. Remember the lesson – wide diversification and keep investing.

There will be the lure of emerging markets and big gains. Emerging Asia will overheat and crash in 1997, causing global falls. There will be the lure of super-economies. The Chinese bubble will burst in 2007 and lead into the US bear market. The same will happen in 2015 with a Chinese crash starting a global decline and the year's gains being wiped out.

Despite all this, keep investing in Asia.

Lets talk about debt baby. Complicated debt instruments will be repackaged, fogging their true risks. There will be a massive failure of financial institutions in the US, resulting in bank failure worldwide. You will personally see people queuing at cash machines in London trying to withdraw savings. The New Zealand government will be forced to place a guarantee around bank accounts and watch as failed Kiwi finance companies wipe out a generation of retirees.

Governments worldwide start printing money.

What should you do? Keep investing.

By the time you're 40, the Greeks can't pay for anything and nearly bring down the whole of Europe. Sharemarkets decline globally. Again, just keep investing.

Crash, bang, bump, pop

So what am I going to do about this looming crisis I've predicted with utmost certainty? Nothing. It's exactly what I've done through every single one of them. Actually, that's not quite true. They've caused impatience, frustration and a bit of moaning. Yet they've never caused me to sell anything.

Continuing to invest through every war, currency crisis, debt crisis, tech bubble, credit crunch, emerging market meltdown, Chinese free-fall and banking crisis has always resulted in being in the right place for all the gains.

When you summarise the chaos, my life appears to be a wild ride. Yet as a line on an investment chart, it's been a great run. Shares outperform every other asset class over the long-term, so long as you stay put.

Major sharemarket downturns

Black Monday: October 19, 1987

Friday 13th Mini Crash: October 13, 1989

Early 90s recession: July 1990

Japans asset bubble: 1991-2011

Black Wednesday: September 16, 1992

Asian Crisis: July 2, 1997

Russian Crisis: August 17, 1998

Dot-com Bubble: March 10, 2000

September 11: September 11, 2001

Downturn of 2002: October 9, 2002

Chinese Bubble: February 27, 2007

US Bear Market: October 11, 2007

Global Financial Crisis: September 16, 2008

Dubai Debt Crisis: November 27, 2009

European Sovereign Debt Crisis: April 27, 2010

Chinese Crash: June 12, 2015

Selloff of 2015-16: August 18, 2015

Janine Starks is a financial commentator with expertise in banking, personal finance and funds management. Opinions in this column represent her personal views. They are general in nature and are not a recommendation, opinion or guidance to any individuals in relation to acquiring or disposing of a financial product. Readers should not rely on these opinions and should always seek specific independent financial advice appropriate to their own individual circumstances.