i might not totally agree with you that while investing in bitcoin you should just set up a plan of accumulating 2 bitcoin and use the whole of your life in getting to that planned figure.
Yeah it is of the nature of every investors to dream big about their future accomplishment, so setting a reasonable target is good way to start the process but not every target is encouraged, so actually I would say that having a set target of 2 Bitcoin to achieve in all of his life does not sound like a target because the conviction will be very low and as the time goes you will start losing interest because of the belief that you still have a good number of years ahead of you to meet up and from such mindset other things will come in play and occupy your mind from thinking about your investment, meanwhile as we normally talk about few years targets is better because it gives us the discipline that whatever thing we do we have something very important to reach out and that idea will now be installed on our head.
I personally don't have a set target for the number of Bitcoin that I want to accumulate into the future, because I don't want to put myself into unnecessary pressures to achieve the goal by all means. Although there's nothing wrong with setting a soft target for yourself into the future, perhaps in 10 years time to achieve a reasonable amount of Bitcoin but there's no need to over labor yourself or deny yourself of basic needs that are essential to live a healthy lifestyle because you want to accumulate 1 or 2 Bitcoin within the timeframe.
DCA method for example gives you the ease to accumulate according to your income at any particular time, no need to overpressure yourself and miss out on having a meaningful life by overstretching yourself in the cause of wanting to meet up with unrealistic targets that your income can not accommodate. It'll be unwise to stash your bag with a reasonable amount of Bitcoin in the future then not be in good health or sound mind to enjoy part of it in your retirement or worse don't even be alive to enjoy it. What I focus on is the percentage of my income that I set aside for my DCA method, that is where I have a constant for my accumulation, not the amount of Bitcoin that I must have in my retirement.