For sure I am battling this right now. I think it's because we are just BUSY.
I can manage some of it.
Food: Right now our food bill is creeping up. Not because we are eating out, but because it's just *easier* to buy the same things every week, and to use a produce CSA that delivers, than it is to scour the sales and shop at 3 stores. So, sticking to my old budget was getting really really hard in the first place. Then add lack of time...
Entertainment: We don't go on dates much. Not compared to many of my friends, who go out to fancy dinners, weekends away, and concerts. That all adds up BUT the babysitting will kill you. I have found that we are going on more dates now (6-8 per year, vs. only 1). You know, date night is $50 in babysitting. My friends are no longer interested in babysitting swaps. We can keep the date night costs low aside from that by being smart. We could do lunch dates, but our work days are pretty packed as it is. We could skip dates, but having been married for almost 20 years with kids at 10 and 3...we need dates. So yeah, this year, I'm letting date night lifestyle creep happen. We're going on a date this week, and going to a concert in June. I want to take the day off on our anniversary and do something fun, like go kayaking and have a leisurely lunch.
Travel: We also don't travel much because it's a pain with the kids. But generally we fly to visit family every other year. This year is not one of those years, but our niece is graduating from HS, and we decided to go. And it's complicated, with 4 people there, 3 people back (leaving the 10 year old), and one fperson back out, and two people back.
Social: I get a lot of my social interaction on the weekends at our potlucks. But honestly, there are people who are special to me that I don't get to see that often (former coworkers mostly). I need to make a special effort to see them, and that generally involves lunch out.
Kids activities: my son recently started playing baseball. I've resisted much of the lifestyle creep (group trips to the Dodgers, buying a bunch of raffle tickets), but not others (opening day costs, taking our turn as the "snack parent", buying snacks at the game - a few bucks, getting a $1 snack at swim lessons once a week).
I guess it gets tiring saying "no no no no" all the time.
Wine: my taste in wine has gotten more expensive. So I'm trying to drink less.
Clothing: I did pretty well with the "no new clothes" in 2015, mostly just swim suits. But this means that much of my summer clothing (shorts) are terribly ill fitting. I found myself dreading the summer. I finally sucked it up and bought 3 pairs of shorts and a pair of capris. Yes, I could have scoured the thrift stores, but I hate shopping.
On the flip side, we've had a lot of free lunches at work lately due to interviews. I got free lunch yesterday (with enough for dinner). When I left, there was still a HUGE bowl of salad left, so I covered it and put it in the fridge. Guess what's for lunch today? And when I'm done, I'm washing out my bowl and filing it again for tomorrow.