Usually trades go really bad when you BELIEVE in something, yet refuse to look at what the facts are showing. This can be said another way - Don't confuse your opinion of a company with the stock of that company - they are entirely different things. You may like a companies products and even have lots of friends who do. If your idea is sound, others across the globe (eventually) will enjoy the product as well and the stock WILL GO UP. What happens most of the time though, is personal opinion refuses to look at the stark fact that the funds/market has the exact opposite opinion. Sure you have to give it some room, but there is no reason to ride a stock down 50-70% because of personal opinion. That is a sure road to the poorhouse. Also remember - if you stop out you can always get back in again if you think it was a mistake. It's easy, hit the buy button.

I agree with MMP

Sounds a lot like Warren Buffetology. Stay within your circle of competence.

Better to know your limitations and work in areas where you have a better chance of being right. No one learns anything by being consistently wrong in an area where they're clueless. Back to the basics is a good idea under such circumstances.

Hopefully you aren't always wrong, otherwise you aren't learning from your mistakes.

Agreed! It is better to wrong and learn then it is to never learn at all! But if you are always wrong, then you need to do something different.