I found [u]powerful sustaining motivation[/u] came most from playing songs as an adjunct to the syllabus as soon as I could

Apart from the coincident enjoyment in the challenge of learning to play this instrument, comprehending there are those who aren't motivated by or don't derive pleasure from that, ubiquitiously for the majority making music is why we want to learn to play guitar ...isn't it?

So find those songs you like, preferably love with some degree of passion, either within your current competency (to reinforce) or outside it to (challenge and develop). The latter process will depend upon individual temperament, particularly qualities of perseverance and determination. Amaze yourself.

There are literally thousands of songs you will be familiar with, e.g. "Stand By Me", and be able to play in keys of either G or C with just a simple I–vi–IV–V progression as soon as you can play those open chords. i.e. G-Em-C-D and C-Am-F-G.

[br]Here's my core mantra to measuring progress, maintaining & deriving satisfaction from progress with this instrument. "The only person you should try to be better than, is the person you were yesterday". - unknown

[br]All the best.