This translates as - Parties are really pleasing to me. i.e. They (the parties) are really pleasing to me. The verb gustar is a special case.
my guess because mucho refers back to the person speaking, in this case assumed male. The parties please me a lot.
"Mucho" is an adverb in this sentence (not an adjective). It modifies the verb ("like (a lot)" or "are (really) pleasing."). Because it's an adverb it doesn't have gender or number; it doesn't have to match anything. And, the gender of the speaker also doesn't matter.
It's an adverb. Adverbs have this trick that they seem to have gender because the might have -a and -o endings, but actually they have not gender anyway.
Gustan (multiple objects) and Gusta (1 object) I = Me gusta/gustan You = Te gusta/gustan We = Nos gusta/gustan You (all) [plural] = Les gusta/gustan
I put "festivals"...wrong. DL seems to use "fiestas" for festivals, parties and holidays quite arbitrarily. Am I missing some nuances of usage?
how would one say "I like a lot of parties"? Is this just awkward and you would have to add another verb ("I like to go to a lot of parties", "I like to have a lot of parties", etc)?
I said "I like a lot of parties". Google seems to think that is "Me gusta un montón de fiestas."
You could say "Me gustan muchas fiestas". Since you coordinate muchAS with fiestAS, you mean "a lot of parties". When you coordinate endings in Spanish it means you are saying one single idea. That's the trick.
To clarify, gustar is a special verb that requires the indirect object pronoun (me, te, etc.). Basically, this sentence really means 'The parties are very pleasing to me'. Since the subject is 'parties', you use gustan. Confusing, but important. (Source: http://www.studyspanish.com/lessons/gustar.htm)
Again, the phantom idiom. "I really like parties." means pretty much the same as "I really like parties."
" why i love the parties is not allowed. "me gustan mucho = me encantan", me encanta = i love it