Allaah سبحانه و تعالى said,
"Then High above all be Allaah, the True King. And be not in haste (O Muhammad صلى الله عليه و سلم) with the Qur'aan before its revelation is completed to you, and say: 'My Lord! Increase me in knowledge.'" (Soorah Taa Haa, 20:114)
Qataadah رحمه الله mentioned: "Shaytaan does not spare anyone until he approaches them from every direction. He even approaches them through the doors of knowledge, saying, 'What are you going to do with pursuing knowledge? If only you would first practise everything you have already heard.' If anyone would have sufficed [with the knowledge they had], Moosaa عليه السلام would have sufficed. Instead he requested [Khadir عليه السلام when he met him], 'May I follow you so that you teach me the guidance you have been taught?'" (Sooratul Kahf, 18:66) 
Hence, so long as a person has every intention to apply the knowledge they have acquired into their lives, they should constantly remain in the pursuit of knowledge, and ask Allaah سبحانه و تعالى to grant them more.
Imaam 'Ayni رحمه الله has written, "With the exception of knowledge, Allaah سبحانه و تعالى has never instructed His Messenger صلى الله عليه و سلم to pursue more of anything." 
According to Imaam Ibn Hajar رحمه الله, this verse clearly displays the virtue of Islamic knowledge. This is because Allaah سبحانه و تعالى has never ordered His Prophet صلى الله عليه و سلم to pursue more of anything except knowledge. The knowledge that is being referred to here is knowledge of:
1) Sharee'ah, through which a person learns of their religious duties, such as ritual worship and personal dealings.
2) Allaah سبحانه و تعالى and His Attributes, through which a person can realise the importance of carrying out Allaah's instructions سبحانه و تعالى, and consider Him سبحانه و تعالى to be above all deficiencies.
Knowledge of these factors is encompassed in the fields of tafseer, hadeeth and fiqh.  
 Sharh Saheeh al-Bukhaari, 1:136
 'Umdah al-Qaari, 2:5
 Fath al-Baari, 1:187
 Shaykh Omar Subedar حفظه الله, Commentary on Sahih al-Bukhari, vol. 2, pp. 22-23
See also: Virtues of Knowledge which is Learnt and Taught for the sake of Allah