No one knows where the last dip is. And there's no point in regretting for that dip. You can take time if you are worried about the market conditions. But one should not wait with the intention of buying the dip. At a designated range you can select your buy price and wait for it.
Before investing we should remember that we have to take risks and be motivated to invest for the long term. Mental strength must be kept more stronger. And invest in assets that can bounce back in your expected situation. Where investors have the confidence.
Of course, it's possible to know the last dip. Maybe what you mean is the true bottom of the price? If the dip that happened is huge and you missed it for none important reasons then I think it's regretful but there is no need to regret for a small dip because there is always a chance that it can happen again.
Yes, if a trader or an investor waits for a dip, it will increase its instability that has no end. However, it should be fixed by analysis. The lowest price of any particular coin and the maximum price difference and possibilities in the bearish market should be fixed and buy. However, in the case of Bitcoin, if the price difference is slightly higher, that would not make any bad impact.