You don’t do anything to keep sober.
Sober is a word we use to mean a natural , umolested state of mind/being.
Not drinking (sober) is a passive state , artificially incorporating intoxicants in one’s system is an action . Viewing keeping or staying sober as being a result of actions taken is reversal of cause and effect, yeah?
Being or staying sober isn’t really a choice, it’s pretty much metaphysical .
Drinking is making an action choice. The AV portends the near inevitability or practical metaphysical-ness of more drinks.
You don’t stay sober by not drinking , you don’t get drunk.
And only AV portends an inherent difficulty in being in a natural state.