I think you're correct here investing in bitcoin is not only all about having a long term mindset, you also need to put down some measures to safe guard your bitcoin investment for the long term, because I myself personally believe that it is not only the amount of bitcoin you are holding in your wallet that will determine your success in your bitcoin investment journey, for there are some measures you have to put down which are: securing your bitcoin wallet from thieves and scammers, also by setting up emergency fund and backup fund to enable you not to temper with your bitcoin holding, if in case emergencies arise along the line, so that there will be emergency fund to handle those emergencies instead of tempering with your bitcoin holding.
You've made a very important point, it would be a waste of time and heartbreaking to invest for years then lose what we've been holding for years to scammers cause of our carefreeness or failure to secure our portfolio, the security of one's portfolio is as important as holding for long-term, that's another area newbies should concentrate on as well as learning to hold Bitcoin for a longer period.
Also, owning an emergency fund shouldn't be overlooked, to maintain a healthy portfolio it's very important too, emergency situations are something that's not planned, they can happen anytime which is why investors need to be very ready for a worst case scenario and there's no other way to be prepared than having the emergency fund intact.