The situation would change, if I were Adam, first man in the world, and a priory will be able to start exponential human growth with P= 50 per cent probability (or think so). After finding that I am Adam, I would have to update this probability to lower. The way I update depends of sampling method - SSA or SIA but both result in early doom. SSA says that I am in short world. SSI said that my apriory estimation of universal distribution of short and long civilization may be wrong. It would be especially clear if apriory P would not 50 percent, but say 90 per cent.