It says in the sefarim that sometimes we didn't have full bechirah in the past. Never let the past concern you at all. If that is the ONE thing you learn from our entire website, it will have been worth it.
1. About lack of bechirah, do you remember mekoros? It is something that I keep thinking
might be the case, but do not know of any source for.
2. To say that one should
never be concerned about the past, does not sound right at all. This is something that is a huge topic, is discussed a lot and depends on many things. I'm sure you know all of this. Sometimes this has to be done, but certainly not always. "Never Say Never," is an understatment here. "Never let the past concern you at all if attention to the past will impede your progress forward", may be the appropriate statement here. That admittedly is often a major stumbling block for many people, many times. But it is not something which always applies at all.