I prefer the mantra "One who puts on his armor should not boast like one who takes it off."[0] I take it as advice not to talk about anything that isn't finished, which spurs me to finish more things so I can talk about them.
[0] Disclaimer: From a really old book, might be superseded by newer material (1 Kings 20:11)
To reinforce your point, the act of talking about a work-in-progress can actually give your brain a reward similar to actually finishing a that task, sapping your drive to finish things and increasing your drive to start more things, just so you can talk about them.
Before I picked that up, I started a lot of things and talked a lot about them. Now for any endeavour I find myself making early decisions to push through and finish or move on ASAP. Among other things, it's meant far less time spent on books I don't actually want to be reading.
[0] Disclaimer: From a really old book, might be superseded by newer material (1 Kings 20:11)