It's not irresponsible to spend money on traveling and adventures. You get back much more than nice time there and couple of photos and souvenirs - you are exposed to new environment, people, culture etc. and you'll grow inside in a subtle, yet steady way. On the other hand, usual "buying stuff you don't need to impress people you don't care about" is useless, and won't even bring any long term happiness.
You always pay over the odds to rent initially but due to inflation and relative property prices it becomes good value rather quickly.
London is one of those crazy places where a job jump can actually get a salary boost larger than the national average salary in its entirety which is where the short term advantage is if you know how to play the market.
I live in London, UK in a flat I rent for £950 pcm. This would cost me £379,000 to buy, at the very least as it's a relatively nice area.
I could scrape the deposit and get a £379,000 mortgage but the insurance, maintenance and other costs on top would result in zero disposable income.
Currently I have £1750 left over every month which is nothing but bags of freedom to do whatever I want.
If I was to drop dead on Monday, the last great event wouldn't be getting Magnet in to do my kitchen, painting the living room ceiling and sitting in all weekend eating Tesco Value food. It would be chilling next to Lake Geneva in Lausanne with my other half which is exactly what I'm doing.
Live life now before it's over.
Edit: This is based on the advice of my wife's grandparents who are just about hanging on at the age of 84 and 86 respectively. They had to cancel their cruise this year due to poor health and openly admit that they worked way too hard for a house. They have a nice £1m house in London and a pile of savings but it's worth nothing to them now because their health is gone. It's empty as the children have left and they realised the memories were more important than the bricks.
So, sod buying a house. I'll live an irresponsible yet fulfilling life now.