The word "alot" does not exist. It is often mistakenly written instead of "a lot" which is the correct spelling.
This was drilled into my head all through elementary school, just like it ain't proper to say ain't, but for some reason I keep wanting so bad to use it that way.
A lot as one word feels more normal to me, just like many, much etc. which are all also one word and not two. So what's the big deal?