The anger about the new all-time high the S&P 500 is currently approaching is palpable. Take my word for it, I read everything and everyone.

The 14.5% rally off the February lows, on nothing but worsening earnings and cuts to GDP forecasts has people utterly furious. I’m trying to remember a time in which stocks were on the verge of a breakout and people were so angry about it. The Dow just broke above 18,000 for the first time in nearly a year, and no one wants to even smile.

I think a lot of this stems from the seeming disconnect between a sluggish economy and record high stocks. Another component of it is the anxiousness that people feel so soon after it looked like a full-blown bear market could be upon us. There was recession talk in the air as recently as last month as well. People who did something to protect themselves – selling, shorting, hedging, etc – are absolutely furious. And it’s entirely understandable.

One of the things I am thankful for personally is that I stopped playing the guessing game professionally about where markets were headed roughly six years ago. The game was endlessly frustrating and I was never any good at it anyway. Running money based on evidence and rules, as we do today, has made a huge difference in my life. I can’t imagine ever going back to the way things were for me from 2000-2010.

When I think of all the time and energy I used to spend trying to guess at the unknowable, I shudder. When I see people still doing the same thing – making emotional calls about buying and selling based on the last thing they read or the feeling they woke up with, it’s amazing to me – even though I played the same game myself for so long. How can they seriously be doing this? With real money?

Anger at new highs or because of a correction or bear market is symptomatic of process-free investing. I know this from experience, and I’m thankful for this experience even though it felt terrible at the time. It taught me what not to do.

Rules-based investing isn’t a silver bullet, nor will it ever remove the discomfort that every market participant is forced to feel from time to time. But having a rhyme and reason, laid out in advance, for the decisions you will and will not make, is utterly priceless in comparison to the alternative. An alternative you couldn’t pay me to regress back to.

Life is too short to be spent placing seat-of-the-pants bets in a casino where the rules change every week. Don’t get mad, get disciplined.