Most traders sooner or later lose their money. Trading is very much like a casino only having much more opportunities to both increase and lose their capital.
You need to be aware that any transaction can be unprofitable and calculate their risks accordingly.
so simple rule which all of us know why then we keep failing
The comparison between trading and gambling is also quite a lot on this forum, it is quite true for newbies. Newbies are often tempted by super profitable forms, they bet without analysis, losing money often happens at the start of joining.