Redirect loop with node express.js

I have simple webpage with /about, /contact, /home and /lessons routes defined. All routes work okay except for /lessons. I instantly get a redirect loop (Error 310 (net::ERR_TOO_MANY_REDIRECTS): There were too many redirects).

Here's my main server.js code :

var port = process.env.PORT || 8888;
var app = require('./app').init(port);
var markdown = require('./markdown');
var lessons = require('./lessons.json').lessons;

// app.use(function(req,res,next) {
//     console.log('adding lessons to locals');
//     res.locals.date = new Date().toLocaleDateString();
//     res.locals.lessons = lessons;
//     next();
// });
// app.use(app.router);

app.get('/', function (req, res) {
    console.log('controller is : home');
    res.locals.controller = 'home';
    res.render('home');
});

app.get('/:controller', function (req, res, next) {
  var controller = req.params.controller;
  console.log('controller is : '+ controller);
  if (controller == 'about' || controller == 'contact') {
    res.locals.controller = controller;
    res.render(controller);
  } else {
      console.log('next was taken!');
      next();
  }
});

app.get('/lessons', function(req, res) {
  res.locals.lessons = lessons;
  console.log('controller is : lessons');
  res.render('lessons');
});

app.get('/lessons/:lesson', function(req, res) {
    console.log('controller is : lesson');
    res.locals.controller = 'lessons';
    res.send('gimmie the lesson');
});

/* The 404 Route (ALWAYS Keep this as the last route) */
app.get('/*', function (req, res) {
    console.log('got 404 request to ' + req.url);
    res.render('404');
});

and here's the app.jsfile which is used for server initialization:

var express = require('express');
var slashes = require('connect-slashes');


exports.init = function (port) {
  var app = express();
  app.use(express.static(__dirname + '/public'));
  // add middleware to remove trailing slash in urls
  app.use(slashes(false));
  app.set('views', __dirname + '/views')
  app.set('view engine', 'ejs');
  app.use(express.bodyParser());
  app.use(express.methodOverride());
  app.use(express.logger());
  app.enable("jsonp callback");
  if ('development' == app.get('env')) {
    app.use(express.errorHandler({
      dumpExceptions: true,
      showStack: true
    }));
    app.use(express.logger({
      format: ':method :url'
    }));
  }

  if ('production' == app.get('env')) {
    app.use(express.errorHandler());
  }

  app.use(function (err, req, res, next) {
    console.log('Oops, something went wrong');
    res.render('500.ejs', {
      locals: {
        error: err
      },
      status: 500
    });
  });

  app.listen(port);

  console.log("Listening on port %d in %s mode", port, app.settings.env);

  return app;
}

I have tried debugging the app with node-inspector but it's useless since the app doesn't seem to go into any of the app.gets to try to match. It immidiately gives me the error when I try to access localhost:8888/lessons

EDIT:

I think I have found the root of the problem :

• My /public dir has a lessons folder
• My /views dir has a lessons.ejs view

When I change /public/lessons into /public/lessons11 for example, the problem is resolved. Can someone explain to me what's express flow in the original scenario that causes the redirect loop ? also, what can I do to resolve it ?

Thanks