We have the same problem. Upon retirement in 2013 I finalized the budget at $32k. We barely spent that in 2014 in spite of having a $9000 major exterior renovation project on the house (deferred maintenance). Then in 2015 we only spent $24,000. Way below what we could spend based on a reasonable withdrawal rate for a 30-something AND I was starting to get some pretty decent side hustle income flowing into the checking account.
So for 2016, I raised the budget to $40,000 per year because, hey, you only live once, right? Might as well try to make sure you're doing it right. We spent $39,000 but $8000 of that was a used vehicle purchase to replace our 16 year old cars. So far 2017 doesn't look like we'll hit $40,000 but we'll try
We're spending 9 weeks in Europe however half of the trip expenses were already paid during 2016 (lodging, flights, lots of airline points spent).
Through March 2017 we are running $3,000 under budget (just under $7000 spent vs budget of $10,000 for Q1). So 2017 might be another low spending year too.
Things I'm doing to try to spend more money:
-tell myself "yes, we can afford it" whenever it's a purchase or expenditure that will be highly rewarding (travel, gadgets, outsourcing not fun home maintenance tasks)
-be looser with replacing things (kid stuff, clothes, shoes, electronics, etc)
-gift more generously
-host more parties to treat friends nice (kind of failed in this regard; life gets busy
)
-don't worry about the $1-10 expenditures as much. Driving 20-40 miles for something kind of frivolous used to bother me but now it's no big deal. If the grocery store overcharges me by a buck I'll no longer go back in the store to get my $1 back.
-occasionally go out to eat or get takeout even when there's perfectly acceptable food inside the fridge.