After almost 5 years in this hobby, I have to say all my personal initial goals have been achived.
I've been able to grow the trees I've decided, to style and propagate them, to create forests, penjing, saikei,... The only one I've not achived yet is a house in a bonsai tree, but it's 90% done yet. The goal to see them become more and more beautiful will be achived in the years to come. I know new horticultural goals will come, but right now I have none. Sorry if this sounds pretentious, but it's the truth.
But I have a goal I initially didn't thought: to finish this "watering slavery" I am into.
So my actual goal is to establish an "effective" automated watering system, and when I say "effective" I mean one in wich I can rely for at least a month, with no harm to the trees in my garden. This goal seems to me hard to achive, as I've learned each and every tree in my garden has somehow "special watering needs", that I know how to satisfy. So I'll have to customize the watering for those special needs at least for a month....