When planning an arduous hike much faster than previously done, carrying a lot of weight through rotten snow, backpacking too early in the season, or any of the myriad ambitious claims that seem to occur at this time of the year, remember the words above.
It is good to have plans and goals.
But do your research, plan accordingly, have alternate plans, and perhaps take on something merely challenging as opposed ridiculously ludicrous.
Hence the phrase “Always have plan B”