I says

do you think if your heart is satisfied with some thing, it is necessarily something good? 

NO it is not. our heart and brain are not capable to think about which we cannot grasp a thing. we do not know what is coming in future, so we simply cannot blindly look into our hearts and jump off the cliff, nor can we decide about what goes well with us. in ever matter of life, we are dependent on the one who is independent in every aspect i.e. ALLAH swt. HE created us and HE knows what is better for us, this is why we may not find our heart's consent in most matters of din at first when we do not think deep about them. but once when we know the wisdom behind the matter, we will be at peace. 
i was listening to the recitation of holy Quran when these words drilled into my brain and i could only then, understand why our heart's suggestions are not enough. go through the verse and then i will tell you more about why it clicked me.

*Al-Quran 20: 96*

*Samiri) said: "I saw what they saw not, so I took a handful (of dust) from the (hoof) print of the messenger [Jibril's (Gabriel) horse] and threw it [into the fire in which were put the ornaments of the Fir'aun's (Pharaoh) people, or into the calf]. Thus my inner-self suggested to me."* 

this verse talks about a man samiri who made a calf i.e an idol for bani israel to worship. 
this verse highlights two most important points, 
1: we should never associate some special details to something which is new to us. for example, samiri saw angel which others could not see, he took the dust from the foot steps of the angel and put in into that idol. WHY? ever though why? because he thought that he saw something simply because he was blessed. or he thought that this was the SIGN? now ask sign of what? its common human mentality that he gets inspired from those things very easily which are not familiar to look out of the world to him. samiri was also inspired so he did that heinous act. for which we was punished not only in the this world but he was also told of the punishment in the hereafter in the following words: 

Al-Quran 20:97
Mûsa (Moses) said: "Then go away! And verily, your (punishment) in this life will be that you will say: "Touch me not (i.e.you will live alone exiled away from mankind); and verily (for a future torment), you have a promise that will not fail. And look at your ilâh (god), to which you have been devoted. We will certainly burn it, and scatter its particles in the sea." 

2: point number two in this verse is the heart? should we listen to our heart and rely upon its suggestions blindly? NO why??? well here is the answer... our brain starts producing reasons behind our actions right from our child hood. now a child may find it absolutly okei to play with a knife because his heart is not alarmed. but his elders surely are scared when they see knife in his hand. child has no knowledge of what he is doing because compared to his elder, he is innocent and fragile. he lacks that knowledge to live and t survive. thats why parents specially spend more time with those kids who are , according to them "problem child".
similarly, we humans are not aware o what we do even when we are at peace. we need a guide every time. so when some one tells us something good, we should not be proud to reject it but we should pay heed to the word of wisdom. 

the verse was truly a message for me, i hope it is also a message for you too. do share it if i was able to elaborate my point. assalamualikum wr wb