Secondly, a question about compound verbs using 〜込む. I know that typically compound verbs of this type tend to add a specific meaning onto the verb -- 〜だす usually means to begin to do the verb and 〜あう usually adds a meaning of reciprocation or mutualness (抱く meaning to embrace and 抱き合う meaning to embrace one another). But what I can't seem to figure out is what 〜込む adds to the meaning, especially since the verb by itself has so many different meanings. Is there a consistent meaning it adds to compound verbs, or does it tend to vary based on the verb, unlike 〜だす and 〜あう?
Thanks!