In life, what would make you "weak in the knees"?

Oh, I interpret weak in the knees very differently from the examples you gave. Something that gets you excited is the way I take it as in the song lyrics “she loved me so naughty made me weak in the knees.” In my interpretation, it would be kindness from a male friend that would make me “weak in the knees.” Going by what you mean, I would say my husband’s leaving me made me almost “weak in the knees” but I’ve have continued being able to walk….

Blood and gore. Emergency room stuff, car crashes. Experiencing people in pain.

To me, “weak in the knees” is a positive thing. Like when you’re in love or infatuated or really passionate about something

The expression “weak in the knees” refers to something that is extremely pleasurable or exciting, generally regarding love or attraction. It’s quite the opposite of what your question suggests.

I have the same interpretation as @janbb. What has made me “weak in the knees” was my husband singing in my ear while we danced.

An earthquake striking whilst I happily trampolined.

Women. And power ballads.

Pregnancy
The death of a good young friend.
Watching my dog being mauled, fighting and being helpless to free him.
Finding love that continues to evolve and grow for the positive.

I usually got weak in the knees over great things, not bad things. Bad things make me dig down for my strength.

I have experienced getting weak in the knees over a bad thing. I can see how it can be positive and understand the connection to things like love etc. but I can’t say I have experienced that feeling personally. Good things are more likely to make me jump for joy. For me, I am more likely to go weak at the knees (and have) over losing those I really love. It would likely be a sign of me being devastated. Losing one of my children or my husband would make me weak at the knees.

An arrow.

@ragingloli When you’re serious, you have great answers, but everything else is BS, so give me the good stuff.

In a positive sense (which is how I interpret the phrase, as well), falling in love. In a literal, negative sense, hearing the unexpected news of my grandmother’s death.

A long, deep, passionate, tender, perfect kiss. That makes me weak in the knees.

A bee sting in my knee.

The closest I’ve come to the literal experience is very close encounter with a large black bear on the AT. We stared each other in the eye for a moment, she turned one direction and ran off and I turned the other (and walked very quickly).

Positive: Someone I like telling me that he surprised himself, but is finding himself thinking about me all the time.

floating above ground…siiigh…..

Negative: The most recent… finding out about the ex planning a farewell party for me.

Large crowds, extension ladders, wasps, hornets, and yellow jackets.

the sound of a beautiful trumpet. It does make me weak in the knees.
and he has for 30 years

Positive: Falling in love (even when it’s over and over with the same person).
Negative: The sudden death of a loved one. Also, squirting/pulsating blood ..it makes me ill.

I agree with @janbb et al, I always thought it of it as a positive. What made me weak in the knees was being kissed by my first love. Nothing else has ever affected me so deeply as that.

On the negative side, and I don’t know if this counts, because it isn’t really “weak in the knees,” it’s below my knees but: I have never thought of myself as a person who is afraid of heights because it’s never been disabling and I’ve jumped out airplanes even, but if I am up high enough in a building that isn’t completely enclosed, like a high-rise office or apartment building, on a balcony or on a cliff, like some kind observation point, even if there is a barrier, if I get close enough to the edge I get this incredibly uncomfortable, squirrely sensation in my shins and calves.

Oh no, that makes me weak at the knees too @lillycoyote! I had to crawl across one of those bridges that you can see through once. I got onto it and then was like… eeek… I am scared of heights. I didn’t care if I looked like a fool. I had to get on my knees and crawl across it. I had to do the same once on a cliff too. I think that is a brilliant example. Well thought out Ms Lilly.

@Bellatrix I’m glad I’m not the only one. That cliff: I thought I might die that day. My legs got so weak I was afraid I was going to collapse and fall over the edge!

Feeling total dispair can leve one weak in the knees.
Realizing that nothing is permanent and that life is everchanging helps.
Do the best under circumstances of extreme dispair is all that is hoped for at times like these.
Give what you are capable of at the time.

Almost a year later, being with the guy I love and being on the mountains.

@linguaphile What mountans? Grats.