This is something I learnt/realised this year, and unfortunately it only comes with age and life experiences.
As a teenager/young adult I would observe my mother’s behaviour and vow never to react the same way, or get upset about the same (seemingly unimportant) things. Now that I’m older, I realise I do things differently and oddly a lot like my mother, or people of the same age. Of course that upset me greatly (who wants to turn into their mother??) and I had a bit of a quarter-life crisis, freaking out about getting old, being alone, (insert various other existential crisis’s of a 20-something).
Then I realised, it’s not a mistake, or something to freak out about. I’m getting older, I’m changing, priorities are shifting, things that were once important now seem futile, whereas issues that didn’t occur to me, now have the ability to ruin my day (missing the bus seems like a train smash where as a teenager, I was too busy shopping to consider something as ‘unimportant’ as a timetable).
Not judging people that are in a different phase, and accepting that you will change and be exactly like that when you’re older, is key to a healthy growth in life. That said, try and keep those upsetting things to a minimum. Once you know what bother’s you and why it seems like such a big issue, you can just take a deep breath and count to 10 before you try and figure out when the next bus will come along.