Direct object pronouns always go after the verb.
Typical English word order is Subject-Verb-Object. If you put object pronouns in front of the subject, it will strongly seem that you are trying to express the subject with them.
Some verbs take objects. An object for verb X answers the question "who or what is being X'ed"
I will remind you about this later.
"You" is an object here, it answers the question "who or what is being reminded." Many verbs describe actions that happen to someone or something, i.e. they have a "target." but still wrong.
but still wrong.
The order of words in English is very important. In sentences that are not questions or commands the subject is usually expected to come before the verb. So when you say something like:
I will you remind about this later.
it sounds like you are trying to make the subject of "remind" both I and you. So, reading this, I don't know who you are trying to say is doing the reminding. It doesn't make sense.
You is both the second-person subject and object pronoun, so something like this:
I will him remind about this later.
is easier to untangle. Since him is an object pronoun, I can figure it out, but it still sounds very wrong.
For reference, here's a comparison between English subject and object pronouns.
Person Subject Pronoun Object Pronoun
-------------------- ------------------- -------------------
1st singular I me
1st plural we us
2nd singular you you
2nd plural you you
3rd singular m. he him
3rd singular f. she her
3rd plural they them