Don't mind me, just resurrecting my blog from beyond the grave for the sole purpose of ranting about Mileven
ST fans and Mileven/Mike-antis really be out here missing the entire fucking point of this conversation??? "Mike is lying/gaslighting/in denial! Clearly he doesn't really love her!" (First of all, ya'll literally don't know what gaslighting is, but that's a conversation for another post) No, actually-- it's not about how Mike feels, or even about how he expresses it. It's about how Eleven has PTSD.
Her life in the lab with Brenner essentially taught her that love is conditional, particularly about her abilities. She only received praise or affection if she impressed Papa with her powers; she was shunned and punished if she refused or couldn't do it.
We see this mentality carry over into her life after the lab as well-- if she fails, she feels immense guilt.
Often she pushes herself past her limits, insisting she can do it; because in her mind, if she can't, then she's no longer worthy of love.
Now that her psychic abilities are gone, her whole world has turned into this huge mess of doubt. Throw in the fact that Hopper is gone, they've moved to a new town away from all of her existing support systems aside from Joyce (who is apparently busy all the time), she's struggling to gain acceptance among new peers and is being bullied... She is clinging onto her relationship with Mike like it's the last thing she has, even resorting to lying to him in order to make it look like she's doing well; because Mike can't know that she's failing to fit in! She is so terrified of losing love, and all this doubt has her so convinced that she already has.
On Mike's end, however, all he can see from her letters to him is that she seems to be thriving, even enjoying her life away from him.
He expressed in later scenes that he has his own doubts and insecurities about this, that maybe there's something or someone out there better suited for her, more worthy of her love. This likely contributed to why he avoided the "L" word in his letters.
His own trauma from repeatedly losing her-- and being helpless to stop it-- comes into play, as well; if he allows himself to open up his heart and admit how much he loves her, it'll hurt so, so much if/when he loses her again. At the same time, I'm sure he's terrified of saying the wrong thing that may push her away.
It's also worth noting that Mike is generally not the best at verbally expressing himself-- he repeats himself, makes defensive outbursts without thinking, and awkwardly trips over his words. Mike's love language is his actions, in kind unspoken gestures, in quiet understanding and reassurance. Things that do not carry over well through letters alone, especially if he has no idea that she is in need of reassuring words. He couldn't see that she has been hurting this whole time. He's likely upset towards her for lying to him because he feels like he should have been there for her.
I've personally been there before-- it's hard to explain the mix of frustration and helplessness you feel when you realize a loved one has been suffering without your knowledge, when you feel like it should have been your responsibility to support them and you failed to, even though it's not your fault for not knowing. This entire situation/argument is something I've gone through with my partner; it is so realistic for a relationship involving someone with trauma like this, and it's a very mature thing for these kids to be handling (and Mike actually handled that conversation beautifully, if they wanted them to have an actual fight fight it could have been so much worse). I don't see it at all as an indication of a falling out between Mike and El. This was a necessary hurdle that they both need to work through, it's an indication that their relationship will strengthen from it.
