People learn things in varying orders, yet I presume that most adults are going to have enough basic knowledge to start, which is to be able to calculate approximately the extent to which their income is greater than their expenses - which means how much money do they have left.  If they are able to calculate that they have more income than expenses, then they can get started investing in bitcoin, and the various other matters (that likely relate to their personal factors) they can learn as they go.   

The don't need to know much of anything before getting started, yet of course, their ability to be successful or to help bitcoin to help them will likely depend on their abilities to identify various important aspects of bitcoin and to get bitcoin to work to their advantage with something like a 4-10 year or longer investment timeline. and sure perhaps a life long investment timeline... yet they hardly need to establish any of their parameters at the time that they get started, even though to get started, they likely have to figure out from where they are going to start to source their coins, whether it is $100 per week, $10 per week or some other amount that works for their budget situation. If anyone identifies some issue within themselves that contributes to their not being able to get started right away, then that is up to them to figure out the extent to which they might have matters that need to be worked out prior to starting or whether those matters can be worked on while they are in the process of investing their $100 per week or whatever might be their starting out amounts.