If you try to be a stickler to everything you budgeted on your spreadsheet or in your app, you're going to drive yourself crazy. Life happens.
Have reasonable expectations, try to prepare as best you can, and put aside some money to have fun! Don't go into debt doing it, however don't think you can go through life just working and grinding. You'll need some unwind time.
Develop some wiggle room in your budget for those unwind times. Remember, everything in moderation 🙂