Easy Change wrote to me with a good question in response to my Asset Allocation post:
"I was wondering if you would be so kind as to talk more about when you started investing and/or what age range you are in at this point in your life. I am coming up on thirty soon myself and I find the whole concept of getting to 100k before then (which is what several pfbloggers are shooting for) to be a huge undertaking."
I think I've covered most of this before, in bits and pieces, but to summarise:

I'm 45, live and work in Sydney, Australia. I have a wife, two young sons, a mortgage and no pets. My personal net worth has just hit one million Aussie dollars. I come from a middle class background, have degrees in IT, industrial math and applied chemisty, and have only ever worked as a "wage slave" - first ten years as a scientist for a private R&D company, and then for ten years as for a market research company - working my way up from an entry level quality assurance role to a junior management position. My salary package is currently $8x,000, but until 2 years ago I'd never been on more than $60,000.

I started out investing by saving my pocket money and earnings (paper round, market gardening, and supermarket shelf packer) during high school into a bank account. When I worked during the Uni vacations (as a process worker in a pencil factory) I saved via my bank account and occasionally invested a lump sump ($1000) into government bonds or unsecured notes from a bank-owned customer credit company (AGC).

I first learned a bit about the stock market doing a Business Economics subject at Uni, which included doing "paper trades". As this course ran in the second half of 1987 it was quite interesting! Once I completed Uni and started working full-time I began investing in Individual stocks (using broker research to choose them), and eventually bought my first investment property.

Over time I learned more about stock selection, minimising brokerage fees and choosing Mutual Funds (for overseas stock exposure) that didn't have exhorbitant fees. Later on I began to use gearing (via margin loans) to offset dividend income with tax-deductible margin loan interest - effectively "converting" current, taxable income into tax-deferred capital gains (which, in recent years, are taxed at half the tax rates of current income).

I sold my original investment property (at a slight loss), as it was in a very poor suburb and tenants proved very unreliable. I swore off direct property investment, but then bought another property after I got married, as my wife wanted to reinvest the funds she had from selling her unit back into real estate.

Recently I've diversified my investmenting to include hedge funds, agribusiness investments (pine, sandlewood and teak plantations) and some wine, coins and bullion. I started direct investment into US stocks last year - trying out the "Magic Formula Investing" method outlined in the "Little Book that Beats the Market".

I'll probably reduce my level of gearing this year, as the stock market has had a very good run for several years and I'm ahead of my projections - no point risking reversion to the mean, especially when using margin loans. I'll also add any future wage rises straight into my superannuation (retirement) account, as by doing a "salary sacrifice" it gets taxed at 15% rather than my marginal personal tax rate. They've also recently changed the tax treatment of retirement income from superannuation accounts in Australia, so that they will be tax exempt. This makes superannuation more attractive than gearing shares or property investments for accumulating assets, although there are some limits to what you can invest in via superannuation, especially if I stick with the company-selected retirement fund, rather than opening a "self-managed" super fund.

I reached $100K net worth by age 30. That was worth more than $100K in today's money, as it was way back in 1991. But it was also easier for me than for most people, as I was living at home still (not paying rent or board), and I had no student debt outstanding when I graduated (I paid the HECS (Uni) fees as I went along. And HECS fees in Australia are only around 25% of the full cost).

My accumulation of net worth over time was covered in a previous post.

Worst investment decisions:

* Spending the money I saved up working during uni vacations on a 10" meade SC Telescope. You can buy one today for about the same price I paid back in 1982, and I've probably only used it for a total of ten hours in the last 20 years. Then again, I always wanted to be an astronaut when I was a kid, so it was worth every cent. I just wish I'd got around to building that observatory up at my parent's farm...

* Spending around $1000 on a Sinclair ZX80 computer and accessories in 1980 - I should have bought some Microsoft shares when they listed instead...

* Buying $2000 worth of an unlisted internet stock (GEN) in 1995, which went broke before it could list on the NASDAQ. If only I'd waited and bought Google or Amazon.com instead...