"Trust nobody than yourself" ... I'm not so sure on that one. One pretty much has to ask others and listen to others. To decide if a "coin" has merit, it's needed to look both at the code, the white paper, economics, partnerships, the team, the business plan of the team, the potential competitors, the market situation ... a single person can only do so much.

Success hinges on many factors, and perhaps "word of mouth" is the most important one. Over a time frame of a month or even a year, it's possible to get massively rich if getting in and out at the right time, regardless of weather the technology is sound or not. However, one should by average expect to go in minus if trying to "get the timing right on the right coin". For a sustained value it's important not only that people "invest" in the coin, but that they actually try to use the product and actually find the product useful.

I must admit, I've sort of given up. Steem is the only blockchain technology I'm actually using actively at the moment. To be honest, I see no long-term future of the "flagship", Bitcoin. It will be superseded by something at some point - and I hope it will be superseded by something better.