of course bitcoin is the best for the long term,
However, sometimes some people make the wrong move or lag behind in protecting assets from decline so that they are locked at a lower value, compared to what they bought.
Indeed. Bitcoin is always good to hold for a long term. Many people prefer to hold 3-4 years at least, so they can get good profits.
It is normal if there is a mistake to do sometimes. But we must evaluate it and changes the way, we mustn't do the same mistake. However, if we only focus in Bitcoin investment, I think it is very small chance to do a fatal mistake. We know well how the price changes in Bitcoin and we also know the cycle. So, there is no reason that we do a mistake in Bitcoin investment.
Are there any tips/signs if the bearish season is coming?
You can count yourself about 4 years cycle. You must know it is the first year of bullrun season. We still have 1 year for the bullrun season. But we must be aware that in the next year, the bullrun season can be over at any time. There is no way to know the exact time of the bullrun season end.