The Maliki jurist Imaam Abu Bakr Ibn al-'Arabi رحمه الله once said that a person is not able to fulfill all of the necessary matters that he must take care of, why then should he get into the unnecessary, extra matters that are of no real concern to him? 
If a person starts getting involved into matters that are of no real concern or benefit to him, he will be wasting and losing valuable time. He will be losing time that he will never be able to regain.
For a true believer, the only matters of concern or benefit to him are Islaam, Eemaan, good deeds, the necessary acts that one needs to do to survive in life, such as eating, drinking, earning a living and so forth. These aspects are enough to take up every moment of his life. When will he have time to tum to trivial, useless or harmful pursuits?
A common problem today among Muslims is the endless pursuit and study of matters with very little benefit while, at the same time, ignoring the most important matters that are of great benefit. This is a sign that a person's Islaam is not complete or perfect. In fact, this is a sign that the person himself may not truly understand Islaam. How much time do Muslims today spend studying andlearning the Qur'aan and hadeeth? Compare that to how much time they spend watching television, gossiping about others , debating on trivial points and reading numerous books on detailed political information which neither benefits nor harms them. If a person truly understood and applied the hadeeth: مِنْ حُسْنِ إسْلَامِ الْمَرْءِ تَرْكُهُ مَا لَا يَعْنِيهِ
"Part of the perfection of a person's Islaam is his leaving that which is of no concern to him,"  he would realize that every moment of his life must be spent only in those things that are beneficial to him in both this life and the Hereafter.
Imaam Hasan al-Basri رحمه الله once said, "A sign that Allaah سبحانه و تعالى has turned away from a servant is that He makes him busy with matters that are of no concern to him." 
When a person reaches such a point, he must repent and ask Allaah سبحانه و تعالى to guide him to those matters that are important and beneficial.  Notes:
 For the quote from Imaam Ibn al-'Arabi رحمه الله, see Imaam Muhammad az-Zarqaani رحمه الله, Sharh az-Zarqaani 'ala Muwatta' al-Imaam Maalik رحمه الله (Beirut: Daar al-Kutub al-'Ilmiyah, 1990), vol. 4, p. 317.
 See: Weapon of Mass Destruction Guard Your Tongue!  Recorded by Imaam at-Tirmidhi رحمه الله, Imaam Ibn Maajah رحمه الله, Imaam Ibn Hibbaan رحمه الله and others.
According to Shaykh Shu'ayb al-Arnaa'oot رحمه الله, it is hasan lighayrihi. See: Shaykh Shu'ayb al-Arnaa'oot رحمه الله and Shaykh Ibraaheem Baajis' رحمه الله Footnotes to Imaam Ibn Rajab رحمه الله: Jaami' al-'Uloom wal-Hikam (Beirut: Mu'assasat ar-Risaalah, 1991), vol. 1, p. 287.
According to Shaykh Saleem al-Hilaali حفظه الله, it is saheeh lighayrihi. (Saheeh lighairihi ("sahih due to other evidences") means that as the chain or hadeeth stands alone, it is hasan. However, supporting evidences remove any possible lingering doubt about it and raise it to the level of saheeh.) See: Bahjat an-Naadhireen Sharh Riyaadh as-Saaliheen, vol. 1, p. 141.
According to Shaykh al-Albaani رحمه الله, it is saheeh. See: Saheeh Sunan at-Tirmidhi (Riyadh: Maktab at-Tarbiyah al-'Arabi li-Duwal al-Khaleej, 1988), vol. 2, p. 269.
However, according to Shaykh Fawzi Ibn Muhammad حفظه الله, it is not authentic. He also gives the impression that two other modern-day scholars have come to the same conclusion. They are Shaykh Abu Is'haaq al-Huwaini حفظه الله and Shaykh 'Abdullaah al-Judai حفظه الله. See: al-Adhwaa as-Samaawiyyah fee Takhreej Ahaadeeth al-Arba'een an-Nawawiyyah (Amman, Jordan: al-Maktabah al-Islaamiyyah, 1413 A.H.), vol. 1, pp. 100-109.
According to Shaykh Jamaaluddeen Zarabozo حفظه الله, it is weak. See: Commentary on the Forty Hadeeth of Imaam An-Nawawi رحمه الله, vol. 1, pp. 485-486.
 Quoted in Imaam Ahmad al-Haitami رحمه الله, Fath al-Mubeen li-Sharh al-Arba'een (Beirut: Daar al-Kutub al-'Ilmiyah, 1978), p. 145, and Imaam Muhammad az-Zarqaani رحمه الله, Sharh az-Zurqaani 'ala Muwatta' al-Imaam Maalik رحمه الله (Beirut: Daar al-Kutub al-'Ilmiyah, 1990), vol. 4, p. 317.
 Shaykh Jamaaluddeen Zarabozo حفظه الله, Commentary on the Forty Hadeeth of Imaam An-Nawawi رحمه الله, vol. 1, p. 491.
See also: Wasting Time is Worse than Death!