Saying 'No' and regrets

I find it difficult to say 'No' most of the times. I just feel bad if I want to say 'no' even to a stranger.

Well, just because I am unable to say 'no' today, I spent a 250 dollars to sign up for some massage package.  After I left the shop, I felt kind of uneasy and 'heartache' to part with my 250. I forgot that I only have a few hundred dollars in my spending budget and yet I went to pay 250 for this 'unnecessary package'.

Why can't I say 'no' to the sales person ?  Why I must oblige to her request to sign up the package when I know I would take ages to complete the whole course ?  Why is it so difficult to say 'no' - WHY ?

I really regretted what I did today.  I felt myself kind of like a fool.  How come I scolded myself fool ?
I also don't know.

Whenever I did something or bought something; somehow most of the times I will feel regrets ... not sure why I always regret after doing something or buying something when at first I didn't think of the consequences.

All these years, I have been having lots of regrets ....... of late I have been asking myself why I didn't do this why I didn't do that when I was younger or in my younger days.  If I have been doing this and doing that, I would have been leading a happy life -  perhaps so. 

How I wish time could travel backwards.  There would be lots of things which I think I could do them better if given a second chance.  Sigh....I just feel that I have missed out lots of 'good stuff' in the past which I didn't got hold of it when it passed by me - an example of it is 'getting married'.  I should have got myself married and have a taste of 'marriage life' instead of now always envying other couples.

Now I really find that life is short and I have wasted so much time during my younger days.  I better 'buck up' now and do what I like and love instead of regretting this and regretting that.  I think I must not spend too much time thinking whether I should do this or not.  Maybe should just go with my instinct - my first instinct on things which I need to make decision.