In the past, I used to be teased for "not having a life" because I wouldn't go out too much and/or I'd pretty much have nothing to do day by day.

Now that I have an extremely busy schedule, which includes being a full time student with a full time job, I still try to go out, I've noticed at least twice a month, considering I'm always so damn tired. Of course, each day changes and I make sure to see my friends/family semi regularly and yet, I'm still accused of "not having a life" because I'm so busy.

What does it mean to "have a life" then? Somebody explain, maybe I'm not understanding.

Having a social life

It normally refers to not having a social life, so not having lots of friends and going out etc.
I'm definitely in a similar situation to you

I guess having a life is just an unobtainable pipe dream

As someone else said, it's basically just means going out and socializing with people. So if you don't do that, you apparently don't have a life.

Having fun with your friends and being occupied by things that bring you pleasure.

Not being a Madonna Stan.

Why did I laughed?

Having friends
Going outside of the house
Having a job

basically anything other then sitting inside all day on the computer by yourself

I'm a stan and have a great social life. I mean, there's bingo on Tuesdays in the home.

If I ever find out what it's like, I'll let you know

OH MY GOD Ababahakxiajshavvaacannan

I was already laughing at his then you come in and I'm reading and I thought 'oh great she can't take a joke then THE END I busted out laughing it's almost 2 AM here oh my god

You don't have a life when there's no diversity in your activities. You don't have a job, there's no social interactivies with family or friends etc. So, for example, this is how average your day looks like:

11.00AM - Breakfast
11.30AM - Gaming
14.00PM - Lunch
14.30PM - Going to the supermarket to get some food
15.00PM - Gaming, surfing the web etc.
18.00PM - Dinner
19.00PM - Gaming, surfing the web etc.
2AM - Sleep

Balance in all aspects, I guess.

I disagree with the social life argument. Many still say one has no life if all they do is go out with their friends. It's all about finding balance in life with your social time, work time and personal time.

not a madonna stan with a sense of humor!

I don't know, but I'll let you know when I get one. Hopefully in a few months.