@lukestokes
I like the cut of your gib.

You wrote:

"It's not just a saying, "Only invest what you're willing to lose." It's an important strategy. Long-term thinking requires reason and negative emotions choke reason out. My message is to understand from the beginning what you're investing in or don't invest at all."

There is another very important point when investing: "Know your own psychology". If you don't know it, then your investment advisor will know it after 20+ years.

The point about psychology is this:
An investment may be right and appropriate as part of your strategy.
You may be, financially, able to withstand 100% loss.
You may know everything about the investment, and understand it's good and bad points and its prospects and risks.
BUT...............
'How will you feel if it drops 10% or 20% or 50%... in the months after you bought it. Will you panic and sell everything because the sentiment has changed, global war is about to break out, and you fear investment prices halving again?'

When investing, especially for others, I always put psychology into the equation. For those who don't know their own psychology, I recommend buying a little of the investment and adding more over time. With daily price fluctuations you will soon know if the price changes bother you.

A last point: If you lose money, will your wife divorce you and your children hate you?

Before I made my first bitcoin investment, I discussed it with my wife. Over time we watched some youtube videos, and discussed it. When she understood what other people thought, and what it is, she asked me to do it.

I also asked my 8 month old baby what he thought. He said "Daddy, I'll be your bitcoin baby". See my blog "bitcoin baby".