I think that might come with experience, or age. When I was starting out I was unreasonably concerned with design and implementation decisions. This led to a lot of pointless arguments and hostility.

Now I can’t even imagine summoning up that kind of energy over a work thing. I used to think “old guys” were lazy and apathetic… and well, here I am ;P

Are you me? I used to stress so much and get very emotionally invested in decisions, then I'd get angry when I felt the wrong decision was being made. My last company finally broke me of that habit (but not in a good way). Now I get worked up way less. I'm still just as opinionated but once the decision is made I don't care anymore. I'll advocate for what I feel is the best path forward but I'm not going to lose sleep over bad decisions or pretend that the future of the company rests on my shoulders.

Honestly I was scared to make this change, for the longest time I thought my emotional investment was what made me a good developer, "I actually cared". While that might have helped the companies I worked for, it did not help me nor my general wellbeing. I'm much more laid back and I'm quick to say "I'll implement it however you decide" and not really care about the outcome. I'll aways warn about side effects or how a decision might affect us down the road but I don't get angry anymore.

If you find yourself getting angry at work about decisions or you get into heated discussions how to implement things (like I did) I recommend you consider taking a step back and realizing that it doesn't really matter and it's not worth getting worked up about.