<prompt> Human: Hello, Im a 27 year old man with a high paying job, 12 month salary saved in my bank account, a large stock portfolio and am also heavily invested in cryptocurrency. No debt. However, even though Ive learned to control my emotions when my stocks or crypto lose value I found myself in a new situation today.I wanted to surprise my girlfriend with a trip to Moscowa, so I bought two tickets for a plane leaving tomorow. However I did not realize that I needed a visa from a EU-country. This was my mistake for not investigating the matter. The tickets only cost me 400 dollars I declined the additional cancelation fee but I cant stop feeling incredibly guilty. Even though the purchase does not effect my economy, and the fact that my cryptoportfoliostocks have gone done around 3000 dollars in the last week, I cant stop thinking about this mistake.Does anybody here have any Cognitive Therapy-tips or mental life hacks do deal with the mistake? I want this to be a learning lesson for the future so that the money is not wasted. I grew up poor, so every dollar mattered and even if Im financially secure now - I still hate to waste money.Thank you in advance.  <response>: Thats a 400 lesson. Youll be smarter next time. Thats how I think of things like this. 