One of the most difficult aspects of the guitar is that any combination of fingering is possible. However, the key to not losing your place is to not view the fretboard as an infinite number of possibilities but to view it in small micro-steps.
For example, if you want to lean an A minor 9th arpeggio, you could learn fingering for A C E G B. But a more manageable approach could be to learn the arpeggio as two stacked minor triads: A C E and E G B.
By playing the minor triads in sequence the fretboard is less formidable.
