a comic strip

I tried to analyze this picture. I read this comic strip about 3 or 4 times, then I still didn't understand.

Perhaps, It's because I'm "pretty stupid" or just over-thinking.

I looked for a possibility of tricks inside the sentences.

..............

After I forced my friend to explain, I feel like I just got slapped.

Okey!..That's why I do not feel happy nowadays.

I'm just over-thingking, even with this snoopy.

Life should be as simple as.

"No matter what other people say and think, as long as you are happy with who you are."

Snoopy: "I'm happy"