Ageing your wood before you build with it is extremely important. Not doing so can cause a number of problems depending on the species. Wood loses “free” moisture quite quickly and this is what makes it warp and crack in the short term. However even after that moisture is lost (the wood is acclimated to your environment) wood continues to undergo changes which can be beneficial to the sound of your guitar and which can help with stability. The denser woods benefit more from longer seasoning times and I find that the worst is ebony. Ebony ends up glued to the top and the neck, both of which have different rates of expansion/contraction, and it gets inlaid with metal frets which have virtually no expansion rate. Typical problems are cracks where the fretboard meets the top, fret ends which poke out of the fretboard and even cupping over time. All of these things can still happen even with old ebony because it seems to be constantly contracting but good construction techniques, humidity control and using the oldest possible stock can go a long way to prevent them.