I have two cards, both have distinct purposes, both have different perks/rewards. I always keep the expenses low and pay them off a the end of the month.

Two. As of yesterday, $0 balances on each!

I still got my first card (as a student) and upgraded it. Then another for emergencies, or when I've lost/left my other card. I don't bring both cards at once, kinda tempts you to spend.

I currently only have one and even that feels like too many to have in my possession. I don't use it on a daily basis, actually I hardly use it. But then there are those moments when an expensive dinner out with friends comes up or a trip opportunity and I find myself charging it. That always comes back to haunt me.

I recently just got my fourth card.
First card was US Bank Platinum Cash Rewards (4k limit) 2.5 years ago
2. Kohl's store card ($600 limit)
3. Chase Slate (3k limit)
4. Discover More (2.5k limit)

I have pocketed over $100 in cash rewards from my US Bank card. I've maybe saved even more with the discounts/coupons I get for holding a Kohl's card.
Discover More gives 5% back on certain categories, otherwise 1% cash back - just got it and I'm excited to start using it.

Also, I have never paid a single penny in interest or fees of any kind on any of these cards. I just make sure I only charge what I could pay off immediately which means I don't even get close to maxing a card or hitting even 15% utilization on any card in one month.

I am assuming that my FICO score will dip a bit after the recent card addition but probably only for 3 months. I am basing this on the fact that when I added the Slate card it didn't affect my Transunion FICO score when it was pulled three months after.

I'm done getting cards for awhile since my credit available is now basically equal to half my annual income (opps). I decided to take the hit on my FICO score now then later. These cards can grow with me and with time their account ages will raise my FICO score. Well, I may need to graduate to Chase Freedom since the Slate is basically dead weight, but I'm set for years now!

It was nice to know that you are exited about your 4th card, good but what i would suggest is use it wisely. First of all , plan your bill payment ahead and see to it that this can be settled by the payment date. It adds to your points and also it gives you relief on your total dues to pay.
Good keep going, Yes the cards can grow with you and your FICO score. All the very best in your chase to financial freedom.

Just one for emergencies.

Actually, it can be quite the opposite. Part of how your score is calculated is how much of your available credit you are using. If you have 5 cards with a $10,000 limit on each, and you pay them off each month, then your percentage of how much debt you're using from what's available is much lower than if you only had one card.

I'm not arguing that everyone needs 5 credit cards or even one. But saying that your credit score will be ruined is simply incorrect.

I have 3 credit cards... one card was used for buying an appliance 0% interest deferred payment for 24 mos.. it was a great help.
The other 2... I am trying my best to finish paying my balances.. after that, I'd like to get rid of them.