Why am I only getting the content of one of my items?

I have a simple comments app which enables the user to enter a comment into the system via a form and these are then logged onto a list on the bottom of the page.

I wanted to modify it so that a user could click a comment once it is created and it would load up the associated content that goes with that comment.

My schema:

var mongoose = require('mongoose');
var Schema = mongoose.Schema;

var CommentSchema = new Schema({
    title: String,
    content: String,
    created: Date
});

module.exports = mongoose.model('Comment', CommentSchema);

My app.js routes:

app.use('/', routes);
app.use('/create', create);
app.use('/:title', show);

My show route:

var express = require('express');
var router = express.Router();
var mongoose = require('mongoose');
var Comment = mongoose.model('Comment', Comment);

router.get('/', function(req, res) {
    Comment.findOne(function(err, comment){
        console.log(comment.content)
    });
});

module.exports = router;

I have three comments in my system and saved in my database, each with unique contents, But whenever I click on a comment, no matter what it is. I am only getting the content that is associated with the first comment.

Why is this?