People react to me strangely when I explain the "lifehack" of eating an entire apple. I'm not sure if it truly constitutes a lifehack. I suppose it slightly improves your lifestyle in that you waste just a little less food.
Basically, you just eat the apple from the bottom up. You get that bitter core, but it's combined with the savory areas surrounding it, so it's not so bad.
And I guess we're so accustomed to fruits bred without seeds that the most incredulous question I get is, "You even eat the seeds?!"
The answer is that I don't normally eat the seeds because when I eat an apple that way, the seeds are fairly easy to just pop out. If I don't have a trash can handy, though, then I'll eat the seeds.