I bet you are not aware of most of the facts because they are not available anywhere online. I have extracted this information from his biography Playing it My way.
When Sachin Tendulkar was scolded for the innings that made him famous- Sachin Tendulkar and Vinod Kambli became overnight sensation for their record breaking partnership of 664 runs in the Harry Sheild Cup. Sachin Tendulkar scored 326* and Vinod Kamble scored 349* not out and played till the lunch of second day. But Sachin’s coach Ramakant Achrekar wanted them to declare their innings in the morning itself after both the players completed their double centuries. He sent his assistant to inform the same to the two players but they ignored the advice and continued batting. When they were going out during lunch the assistant told them that they are in big trouble. Sachin decided to declare the innings but Kambli asked him not to do it because he was playing at 349* and wanted to complete his 350. So Sachin telephones hos coach to ask him and Achrekar asked him - “How many wickets have you people taken”? Sachin told them we haven't declared yet. Then he said Kambli wants to ask something and handed him the phone. But Kambli was so scare of Achrekar that he didn't came on call and they decided to declare. After the end of match which they won, Achrekar called a meeting where they read out the list of indiscipline by both these batsman including Kambli flying kite in the middle of the match on the ground!!
Sachin Tendulkar had a habit of taking and giving challenges and not just about Cricket -
Since childhood Sachin was a prankster who used to play pranks on his neighbours like throwing water on strangers or plucking mangoes on Sunday afternoons. He was adamant to get a new bicycle as all his friends had one. His father got him one but he got into an accident just a few hours after getting his bicycle. So after a few days he got injured again while wicket-keeping and he didn't had money to take a taxi or go to hospital so he walked down home with blood coming out of his face. After these incidents he started riding bicycle slowly and almost stopped wicket-keeping in cricket.
During 1992 World Cup in Australia, Sachin Tendulkar with his othe teammates challenges Venkatapati Raju to pull the moustache of Merve Hughes (Raju was lean and thin and Merve Hughes was ill tempered and big in size). Everybody thought Raju will get a good thrashing but Raju managed to pull the moustache and escaped unarmed which mad him a hero.
During the India England series 2002 he took up a major eating challenge at West Yorkshire. One of his friend suggested visiting the famous Harry Ramsden’s, in Guiseley in West Yorkshire. This restaurant, served great fish and chips and Ajit Agarkar and Sachin decided to try out the fare. There was one item on the menu titled Harry’s Challenge, whichinvited the customer to eat a giant portion of fish, either cod or haddock, served with chips, bread and butter and two other side dishes. If successful, the head chef would personally sign a certificate for the customer. Since Sachin had always been a big eater, so he decided to take on the challenge. He managed the giant portion of fish fairly comfortably and also polished off the salad and other side dishes served. The only thing he did not eat was the chips, which he thought might be just a little too fattening. Impressed with his performance, the chef signed the Harry’s Challenge certificate.
Music Lover- Sachin Tendulkar was named after the great music director Sachin Dev Burman. The whole Tendulkar family was fond of music. And Sachin was particularly a big fan of Pankaj Udhas. At one point he sent his brother Nitin to Dubai to get the latest album of Pankaj Udhas and waited till midnight to get hold of the casette. Also interestingly when the Indian team went to play Pakistan in the semi-final of World Cup 2011, he asked his teammates if they have the song “Bade Acche Lagte hai” on their iPod. Then he uploaded the song on his iPod and listened to that one song for the next few days on loop to ease his nerves. He also considers O paalanhare as his favourite song at times of adversity.

