I agree.
Conversation needs thinking, but gossip is just meaningless.
I dont like gossip, but I sometimes talk about people who hurt me.
Here's your corrected composition, Jae Seo. Please take a look at the corrections below. Also, send me a message through this website regarding the difference between May I and Can I so I can send you a complete explanation. Have a good one! 
"Conversation is an exercise of the mind; gossip is merely an exercise of the tongue."
I agree.
>>> OR: I agree with that point.
Conversation needs thinking, but gossip is just meaningless.
>>> Meaningful conversation requires thought, but gossip lacks substance.
>>> OR: Engaging in discourse demands reflection, whereas gossip is devoid of purpose.
I dont like gossip, but I sometimes talk about people who hurt me.
>>> I don't enjoy gossiping, but I do sometimes speak about those who've hurt me.
>>> OR: Though I refrain from gossiping, I do discuss personal experiences involving difficult people.