Not speaking of Lent specifically, but abstinence can restore enjoyment as much as teach impulse control. Take chocolate for example; overindulge and it'll lose it's appeal, so then take a month/40 days/etc break from it and you'll be able to eat it again. Or -more anecdotal- in Ramadan Muslims are supposed to abstain from food & sex during the day, this leads to a lot of 'feasting' once night falls as well as a marked increase in sex.
You don't have to do Lent or whatever, but such rituals are/can be quite useful.
As I understand it, Lent is a holiday where we celebrate the scientific method by changing exactly one variable in our lives for 40 days. This seems like a convenient Schelling point for rationalists to adopt, so:
What variable are you going to change for the next 40 days?
(I am really annoyed I didn't think of this yesterday.)