This is a very good read:
http://www.waitbutwhy.com/2013/09/why-generation-y-yuppies-are-unhappy.html
Note the section on how everyone only comments on the highlights of their life and the image that you create in your mind of how well someone else is doing.
At age 25 I have an OK job, a house and two cars. On occasion I have felt 'meh' and want a better car (one of them is the world's cheapest car to run), or sometimes I want a new graphics card, a fancy holiday etc.
Really what I want is to find another half and I have come to realise that buying stuff only temporarily distracts me from what I really want in my life. I am glad of this revelation though as it has driven me to do something about it! I am trying to come across as a more positive person (nobody likes mr grumpy) and have joined a gym.
I certainly do buy stuff I do not need as it brings excitement. However I thankfully only spend what I can afford and have lived my entire life with my parents drilling that into me.
I could get an amazing job on good money, get a snazzy car and wear clothes that aren't from Primark, but on occasion I would still want more. I find the human instinct of greed would always sneak up on me.
Even now I look back and think how I buggered up a year at Uni and dropped out of a PhD........
The hardest part of all is looking in the mirror and saying '**** me my life is actually going well'.
I will always believe a man's house is his castle and will always prioritise my home over PC/gadgets/cars/clothes/holidays, but I do realise everyone is different. I will always want to look like I'm doing well, even if times are hard.
To be honest right now with the house various things are costing me money i.e. New washer and iron this month, which has rinsed me and I could do without the MX5, but it is my hobby and I love it.
TLDR: Click on the link above. I believe impulse buying tat is to distract you from the real problems in life. If you are lonely, you will continue to be lonely once the novelty of a 50" TV has worn off.