What shall it profit us to regret about not investing in bitcoin due to one reason or the other. In life there is what could be regarded as missed opportunity and that means it is a lesson for readiness incase another opportunity will present itself. Many people have criticized themselves for not being early adopters of bitcoin, they believe that those who bought in then are the only ones that have made profit in bitcoin but they simply didn't understand the bitcoin technology, bear/bull and the investment potential of bitcoin.
It’s not worth regretting, it won’t change anything, but we need to remember past mistakes, because that’s how we get those important lessons that will help us do something better in the future, what we did badly in the past. Consistency is also a very important character trait, there are those who are trying to achieve great results in a short period of time, it is often very difficult to do this and it seems impossible, but if you are consistent in achieving your goal, then over time you will definitely achieve it.