Muhammad (prayers and peace of Allah be upon him) was a very simple person and spent all his life in simplicity. He was very unceremonious and informal in his habits. He ate whatever he was given, wore very thick and coarse cloth, even when he was the ruler of a state and undisputed leader of the people. He sat on the floor, bare ground or a mat without any hesitation, alone or in the company of other people. He ate bread made from coarse flour and even spent days on mere dates. He wore simple clothes and did not like display or show. He was by nature simple and liked simplicity and informality in everything.
Ibn Masud (may Allah be pleased with him) said that Allah's Messenger (prayers and peace of Allah be upon him) slept on a reed mat and got up with the mark of it on his body. He said, “O Allah's Messenger! I wish you would order us to spread something out for you and make something.” The Prophet (prayers and peace of Allah be upon him) replied, “What have I to do with the world, I am like a rider who rests for a while under the shade of a tree, then goes off and leaves it.” [Authenticated by Al-Albani]
«مالي وللدنيا؟ ما أنا في الدنيا إلا كراكب استظل تحت شجرة، ثم راح وتركها» صححه الألباني
Ubaid-Allah bin Muhsin (may Allah be pleased with him) reported Allah's Messenger (prayers and peace of Allah be upon him) as saying, “If anyone among you is secure in mind in his life, healthy in body and has food for the day, it is as though the whole world has been brought into his Possession.” [Reported by At-Tirmidhi and declared good by Al-Albani]
«من أصبح منكم آمنا في سربه، معافى في جسده، عنده قوت يومه، فكأنما حيزت له الدنيا» رواه الترمذي وحسنه الألباني
He liked simple living and wanted his family to lead a simple life and abstain from ostentatious living. He often wore thick clothes. His bed was sometimes of rough blanket sometimes of skin filled with palm fibers and sometimes of ordinary coarse cloth. In the ninth year of Al-Hijrah, when the Islamic state had extended from Yemen to Syria, its ruler had only one bed and one dry water-bag of skin. A'isha (may Allah be pleased with her) reported that when he died, there was nothing in the house to eat except some barley.
Once Umar (may Allah be pleased with him) entered Muhammad's (prayers and peace of Allah be upon him) house and noticed the state of the furniture in it. There was one simple bed, with one pillow filled with nut fiber; on one side of the room was some barley and in one corner near his feet was an animal skin. There were some water-bag skins hanging beside his bed. Umar (may Allah be pleased with him) said that on seeing this tears came into his eyes. Allah's Messenger (prayers and peace of Allah be upon him) asked the reason for his tears. He replied, “O Allah's Messenger! Why shouldn't I cry! The strings of the bed have left marks on your body. This is a small room with all your furniture; I can see what there is. The Kaiser (Cesar) of Rome and Kisra (Khosru) of Persia enjoy luxurious living while you, Allah's Messenger (prayers and peace of Allah be upon him), and the Chosen One, live like this.” He said, “Don't you like that they choose this world and we choose the Hereafter?” [Reported by Al-Bukhari]
«...وإنه لعلى حصير ما بينه وبينه شيء، وتحت رأسه وسادة من أدم حشوها ليف، وإن عند رجليه قرظا مصبوبا، وعند رأسه أهب معلقة، فرأيت أثر الحصير في جنبه فبكيت، فقال: (ما يبكيك). فقلت: يا رسول الله، إن كسرى وقيصر فيما هما فيه، وأنت رسول الله، فقال: (أما ترضى أن تكون لهم الدنيا ولنا الآخرة)» رواه البخاري
In short, Muhammad (prayers and peace of Allah be upon him) lived and liked a simple life and enjoyed every minute of it. He taught his companions, through his personal example, to lead a simple life and not to be ostentatious.
Source: Islam Story website