You were either too proud to tell your friends the truth or had bad friends.
It's not my fault I don't want to pay 13 dollars+tip for a cocktail when I can make 20 of them at home for the same price.
We all have choices.
Oh, certainly not your fault, but you might be better staying at home. Why agree to go out somewhere with your friends if you are just going to drink water?
What do you think I'm an amateur? Club soda with lime, in a highball glass.
Then stay the hell home, please. Everybody will be happier.
When I organize something like this either A) I think the cocktails/beer/food/etc. is genuinely amazing and if you don't then you should stay home or B) I'm more interested in the company and I think the ambiance is acceptable.
Even with similar incomes, as young adults in our mid-20's, working hard for our money, we'd like more control over what we end up paying for.
Could be a cultural thing. I live in a small town of a rather poor country. Where I live, friends pay in turns, today I'll pay and the next time he'll pay and so forth... and not even very strict turns[1]. If could split the check in half, that's acceptable. Splitting the bill to the cent would leave you with no friends in no time.
[1]: That said, food here is cheap (dirt cheap compared to the US). If you go to the capital, it's different. I noticed that people there split the bill, but restaurants/food costs 2x or 3x up, so paying the whole thing is expensive.
Also situational. When I was at university, if we went out anywhere, you'd just pay for your food/drinks individually. Now we're all in a position where money isn't as tight, buying rounds of drinks and not paying close attention to who's turn it is or the price of the drinks is much more common.
Being able to pay for yourself feels like control, and it's doubly important to have that feeling when you're poor.
I did make sure to pay them back when I could (a few months later), and when I had a bit more money a few years later made sure to buy them all a few rounds of drinks though.