I don't know a thru-hiker who doesn't look forward to going into town after a few days on the trail. I certainly do. There are many reasons to be excited about it, even if you're spending just a few hours there. Time in town is a chance to refuel, refresh, and restore your body.
You can usually get a shower and do laundry, and those reasons alone make you feel ready for more hiking. Then, of course, is food and drink. When you don't have to worry about carrying it, you can consume extra to add back some calories you missed while on the trail.