Encounter with my childhood friend

One of good friend whom I grow up with approached me recently and asked me whether I will like to invest in CPU for bitcoin mining. He explained to me that you just need to invest about usd6k and you can get minimum usd 600 per month which is about 10-20% return per month. 

I look up online and realize you can buy all these computers from Amazon. However they consume a lot of electricity and produces a lot of heat which requires secondary cooling. It will be profitable if you stay in college or if you live in a country where electricity is free. It doesn't make sense for me to do this on a small scale basis in Singapore. 

So I explain to him that I will rather stay within my circle of competence. If he wants to do it, he can go ahead and the value of bitcoin may increase to 20k in the future. Who knows? This can be very profitable. However I just want to be in stocks and options and moving on to money management business. I told him I have limited resources and time and just want to focus on what I can make money. 

He told me" your knowledge of what's possible is limited by your knowledge of what's possible".

Ok. You win. I am contented.