It really is as @daisy0832 says.
PAY ATTENTION!
Nothing is ever the same twice if you look at it at a fine enough level of granularity. There are always new things, even in the most boring of circumstances.
BE CURIOUS!
If you are curious, which is to say, interested, then of course you can live interestingly each day. If you’re curious, you’ll definitely learn something you didn’t know before.
DO WHAT YOU WANT!
If you do what you want, you will be living as if it were the last day of your life. What you want is made up of a lot of competing desires. This is not an exhortation to be wild and crash your car into wall or spend all your money in a casino. That’s because those kinds of Id-ly wants are always tempered by long term considerations and by the feelings of others you love. Most people want to leave the world better off for their children. So people will still be working on the behalf of others on the last day of their lives.
However, if you do what you want, you will be doing what you think is most important for you to do in your life, no matter whether it is the last day or any day before that.
LIVE INTERESTINGLY!
I’m a little confuzzled here. Do you want to live interestingly for yourself, or for someone else? I think the answer lies within the question. You can’t live interestingly for someone else. You aren’t in their heads. You can only live interestingly for yourself, and if you live for yourself, and follow the above exhortations, you will live interestingly.