[jhanschoo]

I'd like to add that moving from sterile classroom Mandarin to irl Mandarin, you'll notice that

1. You may realize that the tones are realized differently in a variety of ways depending on context, speaker, etc.

2. Just as you can parse a different accent, native speakers can still figure out what you're trying to say if your tones are slightly whack. After all, tonal information in Mandarin is lost when sung.