So here it is in a nutshell.
Assuming you understand how to build a low-cost, efficient portfolio and you know the expected return for the various parts of the portfolio, then you know what you NEED to achieve your goals.
And assuming your need for risk is high than most certainly your ABILITY for risk is low. They are inversely proportional.
A person with a high NEED to take risk usually doesn't have a high ABILITY to weather any significant storms. And conversely, a person with a high ability for risk (say a large net worth or expected large inheritance) has very little need to take risk. Once again, there is no free lunch.
What is left is WILLINGNESS and believe me most people vastly overestimate their ability to stomach losses (risk showing up). Here is one table to consider.
Maximum Maximum
Tolerable Loss (%) Equity Exposure (%)
10 20
20 40
30 60
40 80
50 100
Now really try to consider what it might be like to lose that percentage of your hard earned investment portfolio - maybe for several years in a row because risk is very very real, no matter what the time horizon.
Once you figure that out you are done. And if you can't reach your goal with a level of risk you can stomach, then figure out how to earn more or spend less (bigger yearly investments obviously lower the need to take risk).