The real deal is we're looking down the barrel of a global recession. Oil is cheap because oil futures are cheap. Because, production of manufactured goods is going down. China is the catalyst. The opportunistic disease in the weak patient.
I don't enjoy being the bearer of bad news. Historical econ cycles predict a recession every 7 years or so. The last major correction was 2008 /09.
Seriously, enjoy the cheap gas. But, be ready for rough times. Put some money away. Buy some extra food. Be ready mentally. Your 401k will drop further. But it may take months, or years to "right the ship".
Have some cash on hand. If things get "weird" and there's a bank run, it's best not to be in the middle of that.
This "down cycle" shouldn't be any worse than the 2001 or 1991. But it may be. Every time, it's just a bit different. But the canary in the coal mine is usually lowered production and lowered consumption.
I may be wrong. Let's hope I am. And, prepare anyway. It's going to happen soon, whether it's next week or next year.