So, in the light of the hint, perhaps the answer is
that you are a Lisp programmer, and "those characters" are parentheses, perhaps more specifically (since the hint talks about "the character") closing parentheses:
famously very common in Lisp (a language suggested by the lateral-lisp substitutions in the question)
but I have to confess that I don't see exactly what's going on in the riddle. Perhaps one of two things.
First: Lisp was a very early computer language, and while languages in the Lisp family are still around today they haven't been very popular for some years; and people who like Lisp tend to really like it. So perhaps the idea is simply that when you see lots of parentheses they remind you of the language you love but hardly see any more.
Second: if you are reading a complicated bit of Lisp code and trying to figure out how it fits together syntactically, when you hit those close-parentheses you may then look back at the earlier code to see what open-parentheses they pair up with, which I suppose you could kinda describe by saying "memories come back".
I don't find either of those entirely satisfactory, which probably means either that something cleverer is going on or (if not) that I haven't got into quite the right mindset to appreciate whichever one is right.
A small variation on this theme: perhaps
you are a text editor, or a compiler or interpreter, processing Lisp source code. (And it's the person addressed as "you" in the riddle who is the Lisp programmer.) Then when you reach a close-parenthesis you may actually have to do some kind of backtracking process -- popping a stack, searching backwards in the source code to find the matching left-paren, etc. -- that could be described as "memories come back".