If only I could say that
And not feel so sick and scared
"I don't care"
If only I could say that
If only my eyes would close...
You used to laugh
"Walking these gorgeous blocks...
This top is the place
Where nobody goes
You just imagine
You just imagine it all... "
And know that it's true
Please come back
Like all the other ones do...
All of you...

I read that this song is about Simon, and after he left the band, and Robert missing him...Simon did come back :)

The above comment is correct.
At first glance, this song seems to be about any other painful breakup. He wants to forget, he tries not to care, but it does not work (first verse). The second verse is him reminiscing about better times, when they were still together. The Top seems to be a metaphorical place, the place where you are when you're happy and everything is good in life. And then he realizes all he really wants is to get back together.
But digging a bit deeper in The Cure's history at that point, you realize this lyric is directly addressed at Simon, who he hadn't spoken to for over a year. Actually, the last line suggests he may be directing the song at other former band members as well, like Porl. Of course, they did come back in the end, and thank heavens they did.

lost in pain. but unable or unwilling to let go. escape to the top by what ever means. pain due to loss of love. will she come back?

Yeah. It is a lovesong, but... Or wHATEVER. bUT IT DOES DOES HAVE SOME ALLUSION TO THE pLATONIC METAPHORE OF THE CAVEMEN IN THE CAVE, TIED TO THE ROCKS AND STARING AT THE SHADOWS, ETC... THERE IS THIS ONE GUY HOWEVER WHO ESCAPES AND GOES BACK UP TO THE TOP, and of course regrets it. Just a thought...

A top, like a spinning top. Like a little toy. Little toy, (little..toy)

He's just running back to the top that's always spinning, confusional bliss... I'm just running to the Top..

this song applies 2 me more than ever now. it kills me

Not the meaning but something Smith said about the top:
"Finally coming to my senses - something of a milestone lyric this one - and good fun spending the night getting just the right spinning top sound take!!!"
The Top is way underappreciated. Great album and this is a great track.