Why do guys do things differently as a single man after a break up?

Things I noticed is he has become more active on Facebook and he actually goes out more often.

When we were together, he would never be active on Facebook claiming it was due to anxiety - his display picture is very old and barely posts. But when we finally separated, he changed his display picture and started making new posts. He used to just stay at home and play games even though I would encouraged him to go out with his friends time to time to spend more time with other friends since he used to complain that he don't have friends to hang out other than these friends from out of state. But after we broked up, he seemed to go out and party a lot. Now I am also seeing he is seeing a new girl. He would post pictures of her cooking for him and tagged her as well. Like wthe... it was basically everything I wanted and encouraged him to do when we were together.

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Update… he broked up with me during a heated argument that he isn’t the guy for my needs (basically I asked him to be honest, respect me, and hear me out that he has problems to do)… and he still treated me like a loving boyfriend even after he broked up with me since we lived together until I moved out…

after he kept making new posts and changes on his face book… I slowly started posting myself too… then he blocked me. But I just see his new stuff through his Instagram that’s public.
Why do guys do things differently as a single man after a break up?
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