True that! I use probably 15 days of "unlimited" leave and still manage to feel guilty about it.

The frustrating thing for people in fed jobs is that if you hit your 13 days that's it (during your first 3 years in government). It can be impossible to get PTO until you build up hours again. You have to either quit, negotiate LWOP (often seen as a performance adverse metric on your record), or work. So if you land a sweet concert ticket, see a flight deal, have a friend get married, etc. you better hope you've banked up the leave for it. Since you gain hours every 2 weeks (4, 6 or 8 depending on service) you also start out in government with virtually no leave and can't actually take a 2 week trip until you've been there almost a full year.