title: Doc2Vec not providing adequate results in most_similar
body: <p>I'm trying to use Doc2Vec to go through the classic exercise of training on Wikipedia articles, using the article title as the tag.</p>
  <p>Here's my code and the results, is there something that I'm missing that they would not give the matching results with most_similar? Following <a href="https://markroxor.github.io/gensim/static/notebooks/doc2vec-wikipedia.html" rel="nofollow noreferrer">this tutorial</a>, but I used the wiki-english-20171001 dataset that came with gensim.</p>
  <pre><code>import gensim.downloader as api
  from gensim.models.doc2vec import Doc2Vec, TaggedDocument
  import re
  
  def cleanText(text):
      text = re.sub(r'\|\|\|', r' ', text)
      text = re.sub(r'http\S+', r'&lt;URL&gt;', text)
      text = text.lower()
      text = re.sub(r'[^\w\s]','',text)
      return text
  
  
  wiki = api.load(&quot;wiki-english-20171001&quot;)
  
  data = [d for d in wiki]
  
  for i in range(10):
      print(data[i])
  def my_create_tagged_docs(data):
      for wikiidx in range(len(data)):
          yield TaggedDocument([i for i in data[wikiidx].get('section_texts') for i in cleanText(i).split()], [data[wikiidx].get('title')])
  
  
  wiki_data = my_create_tagged_docs(data)
  del data
  del wiki
  
  
  model = Doc2Vec(dm=1, dm_mean=1, size=200, window=8, min_count=19, iter =10, epochs=40)
  model.build_vocab(wiki_data)
  
  model.train(wiki_data, total_examples=model.corpus_count, epochs=model.epochs)
  </code></pre>
  <pre><code>model.docvecs.most_similar(positive=[&quot;Lady Gaga&quot;], topn=10)
  </code></pre>
  <pre><code>[('Chlorothrix', 0.35521823167800903),
   (&quot;A Child's Garden of Verses&quot;, 0.3533579707145691),
   ('Fish Mooney', 0.35129639506340027),
   ('2000 Paris–Roubaix', 0.3463437855243683),
   ('Calvin C. Chaffee', 0.3439667224884033),
   ('Murders of Eve Stratford and Lynne Weedon', 0.3397218585014343),
   ('Black Air', 0.3396576941013336),
   ('Turzyn', 0.3312540054321289),
   ('Scott Baker', 0.33018186688423157),
   ('Amongst the Waves', 0.3297169804573059)]
  </code></pre>
  <pre><code>model.docvecs.most_similar(positive=[&quot;Machine learning&quot;], topn=10)
  </code></pre>
  <pre><code>[('Wolf Rock, Connecticut', 0.3855834901332855),
   ('Amália Rodrigues', 0.3349645137786865),
   ('Victoria Park, Leicester', 0.33312514424324036),
   ('List of visual anthropology films', 0.3311382532119751),
   ('Sadqay Teri Mout Tun', 0.3287636637687683),
   ('T. Damodaran', 0.32876330614089966),
   ('Urqu Jawira (Aroma)', 0.32281631231307983),
   ('Tiggy Wiggy', 0.3226730227470398),
   ('Frédéric Brun (cyclist, born 1988)', 0.32106447219848633),
   ('Unholy Crusade', 0.3200794756412506)]
  </code></pre>