Ash Shaykh Al Uthaymeen said in Kitaabul Ilm, page 112-113:
I always repeat this point to you ‘applying’ [that which you learn], whether it be in acts of worship, manners or in dealings. Apply it until it is known you are a student of knowledge, and act with that which you have learnt.
We will put forth an example: If one you passes by his brother, is it legislated for him that he gives him Salams?
Yes it is legislated, but I see many pass by his brothers and it is as if he passes by a pillar. He doesn’t give him Salams, and this is a great mistake. Whereas it is possible we criticize the general folk if they were to do similar to this act, then how can we not criticize the student? What will harm you if you said ‘As Salam Alaykum’? How many good deeds will you get? Ten rewards, which equal the whole world, ten good deeds. If it was said to the people, anyone who passes by his brother and gives him Salam he will be given ten Riyaal, you will find the people circling the markets so that they may give Salams, because he will obtain Riyaals. But ten good deeds, we are negligent in regards to it. Allahul Mustaan.
Majid Jawed Al-Afghanee