I have recently switched jobs, having left my first role post-graduation to move to a junior position at a competitor. Now, there was nothing wrong with the position I left, it was relaxed, I wasn't overworked and had good relations with management. Saying that I've made the jump from £25k to £36k per year.
The sheer mental comfort that comes from making more money is genuinely astounding, and far above what I imagined. It works out as just over £500 a month more after taxes and deductions. Three paychecks in and saving a significant amount of money feels so much easier than before, consequently saving up for a mortgage deposit now seems well within range. It's such a profoundly nice feeling of inner calm knowing that I don't have to budget meticulously on every single thing, I can actually relax a bit, I can cover an emergency or splash a bit and not have it come to haunt me later.
There's a notion out there in the social psyche that somehow wanting more money is selfish, greedy, won't make you happy, isn't in some way authentic and that somehow “It's not all about money”. Bollocks to that, the comfort, safety margin and options afforded by having just a bit more money and not having to scrape by makes an amazing, real and profound difference. Don't be afraid to demand more.